Innerdaemon, I am sorry to hear you feel frustrated and upset by where DH and you are in your sex life. I can somewhat relate, having spent almost a decade in a relationship without any erotic interaction, coupled with regular porn use from him.
I apologize in advance as this is probably going to turn into an epic...
A few things that strike me here:
1)Why would sharing sensual pleasures and intimacy with the woman he loves, i.e. sex, "be difficult and embarrassing to talk about" for a grown man? This warrants gentle unwrapping. Does he view sex as a positive, invigorating, fun activity? Or is it somehow connected to negative images for him (dirty, seedy etc.)? What image does he have of women? Does he have a "holy mother or whore" view? I.e. may he think subconsciously you would be degraded by having sex? Did he have positive male role models in his life? Does he feel secure, appreciated and like a true equal in your relationship? Are there aspects in his life where he can feel "manly" and in charge? Does you DH feel comfortable with talking and laughing during sex? Sharing his likes and dislikes?
"As I said he struggles to talk about it, and it usually ends up with me talking and him just listening to me going on about how I would like us to be more open and have more sex. He finds it hard to open up to me."
This is a deep red flag. I would be tempted to go so far as to say, forget about the actual sex and first get into a place where you can have true intimacy of the minds as a couple. If you achieve that, the rest will likely fall into place.
It sounds to me as if the frustrations in your sex life could also stem from issues he has with his male identity and his own sexuality.
2) This "But we didn't just have no sex, it was no intimacy or sexual activity at all apart from cuddling" suggests to me that he may have a rather narrow view about what sex actually is?
Maybe you would both benefit from exploring the idea that sex is NOT about orgasms, that they are not the primary reason for engaging in sex, sex is not over after they happen and they are not the end goal of sex. And, most importantly: they are NOT the yardstick by which to assess whether sex has been "successful" or if anyone is a good lover or desirable.
Maybe invite your DH to "no-orgasm sex", just enjoying touching and exploring your bodies?
3) "But I'm just shocked at how often he does it, when we've not had sex for weeks!! "
I absolutely understand your feelings.
Other people may disagree but in my book, each person is entitled to his/her own private sexuality which includes fantasies, masturbation etc. I think this is is a healthy expression of self, a way to relax and unwind and is not in competition with partnered sexuality.
Do you truly believe he would have sex more frequently with you if he didn't masturbate? This would imply he has a basic sexual need that is mainly focused on achieving orgasms X times a week and if he has Y orgasms through masturbating, you only have X-Y left for partnered sexuality. Somehow that doesn't sound like a very realistic concept of sexuality, does it? Good partnered sexuality is rarely born purely out of a need for an orgasm.
However, if you feel that he uses porn as a way of "hiding" from engaging with you and developing your partnered sexuality (The classic male "head in the sand" approach to relationship and emotional issues.) then there clearly is a serious issue that needs to be dealt with.
I have absolutely no issue with porn in the sense of looking at arousing images. (However, I strongly object to 99% of the porn out there because of the grossly unrealistic kind of sexuality it propagates, the affects of the porn industry on the people operating in it and the blatantly misogynist, inhuman, shallow, anti-empathy views it advertises. I find it incredibly sad that we seem to think it is ok to commodify another human being for our personal gratification. But that is irrelevant to your situation.)
Many women seem to think men consume porn because the women are younger, thinner, more attractive etc. In my experience, men consume porn because it requires no engagement with a real person.
Porn really is a piss-poor substitute for making love. But I suspect that your DH uses porn not as a replacement for sex with you but for the part of his sexuality that is his alone and is ill suited for sharing with a partner. He may want to have an easy, casual, quick orgasms just to unwind, relax and enjoy the feeling without worrying about anyone else. That is a totally valid need but hardly lends itself to involving a partner. (Or may he just cannot imagine how he could share such a sexuality with you.)
For men, partnered sex can be associated with huge pressures, mostly stemming from the idiotic stereotypes about masculinity that are part of mainstream culture. He might think he has to be the active part and "make it happen". He may feel he has to be in charge and know how to please you and what to do although most of the time he feels like he is groping in the dark. He may feel he has to fulfil your expectations (although he is not even sure what they are and how to do it). He may think he is responsible for giving you pleasure and look to your orgasms as a judgement of his own qualities as a lover. If he feels pressured by the stupid myth that real men are always ready and eager he will also worry about his penis (Will it stay erect? Will I come? Is it big enough? Does she even like it?) etc.
Juggling a physical reaction (erection) that is not under conscious control (although he probably believes he should be able to control it - Nonsense!) with the arousal of the female partner is a very challenging task. Not to mention being vulnerable, intimate and in touch with feelings (Yikes!).
Maybe these are things you want to talk about with your DH?
"He has also said that he is really tired and doesn't want to have sex when it takes ages. It takes ages because it sometimes takes me ages to come. I was conscious of this for years when I was younger and I didn't used to bother even trying at all with a man. So I feel that he's essentially saying he can't be bothered making sure I get pleasure."
Maybe.
But you could also understand his words as saying that he is tired and feels there is not enough time to truly relax and make love to you as he feels you deserve.
Sexual intimacy takes time. If he is tired, what changes can you make so he feels he has more energy to spare? I know it is incredibly challenging with kids. But make that time.
I would also consider that his answer is not true in the sense that however long it takes for you to orgasm is not the real reason he doesn't seek partnered sex so often. Particularly when partnered sex is connected to pressures and expectations for him. Maybe he is not telling you "I can't be bothered" but "I blame myself for not making you come quicker/more reliably/whatever and it is stressing me out." or "I feel inhibited/uncomfortable/pressured during partnered sex.".
Do you believe he is responsible for "making sure you get pleasure"? I recommend you take responsibility for that yourself. Sex is not about "tit-for-tat, who got how many orgasms".
I am NOT saying your needs should be ignored. They are JUST as important as his and if it is important to you that both of you have an orgasm during sex, then it is absolutely reasonable that you insist on working out a solution together. Callous disregard for your wishes and feelings and just using you for his gratification is NOT okay. Not caring enough about you and cherishing you enough to see giving you pleasure as something other than a chore is NOT okay. If sex does not give BOTH of you feelings of joy, being loved, desired, connected and happy - then it is pointless.
If it takes time for you to orgasm the way to approach this is not to put pressure on yourself to come quicker, but to find the time. If you really only have time and energy for a quickie, what about raising your arousal level before partnered sex through masturbation? DH just holding you in his arms and kissing you while you give yourself pleasure before or after intercourse?
(Although I would really recommend not getting so hung up about this whole orgasm thing. Just enjoy making love.)
"I don't want to fly off the handle with him, I'm glad he's opened up to me and told me (finally) and I worry that if I go mad with him it'll put him off talking to me,"
I absolutely agree 100%. Attacking or shaming him for his sexuality is absolutely futile and potentially damaging to your relationship. If you judge and criticize a very personal part of him, how is that supposed to encourage him to open up? You want more intimacy, not less.
You need to talk about this. But without blame, aggression and resentment.
I would recommend you reflect about what exactly it is that you miss and want from partnered sexuality. And then have a loving, appreciative, open chat with DH.