Firstly, this may sound harsh but imagine if you wanted sex every day and got it twice a week from someone who was obviously unwilling and not at all into it.
Sex is a tiny part of a relationship if going well but a HUGE part if going badly, and it isn't just you that is unhappy with your sex life.
I totally understand you feel like shit and he isnt making it any easier by being such a child about it but this is something you're both unhappy with.
He needs to stop pressuring you and you need to try making more of an effort, there are times I really cant be othered with sex but once I get into it it's a different story, however DP will make sure he satisfies me which is something your partner isn't doing.
Next time he says it's crap tell him, 'Yes, you're right it is crap, I don't enjoy it because I feel taken advantage of and you don't try to pleasure me, and you don't enjoy it because I'm not into it and don't really want to do it.'
It's a swings and roundabouts situation, you both need to try doing it for each other for a while, him treating you and making you feel special, it's amazing how much sexier you feel after being run a bath and left to drink a glass of wine in there with some candles whilst your partner is downstairs cooking your dinner (or dishing up a takeaway if they arent a great cook!)
Dressing up doesn't need to be nurses and pvc, why not buy yourself some absolutely delicious underwear that YOU like and wear that? Something that makes you feel like a gorgeous woman again?
Tell him to take it slow and let YOU come onto HIM. If he puts all that effort in you can then do the same and not feel like it's a one way street. Make it mindblowing (that doen't mean be filthy, it means connect, get into it, let yourself relax). Hopefully after a night like that he'll realise that it's HIS doing that is making it bad, because you don't feel sexy.
You need to put aside all resentment for it though, think of it as you being treated like a woman should, concentrate on YOUR orgasm, not his. Be selfish.