Oh posted too early sorry OP, i am just going to finish what I was saying.
So you need to take all the heat out of these exchanges. Ask yourself this: is getting angry at him stopping his bad behaviour? Are his angry outbursts and cruel public criticism making you feel loved and wanted? Is it helping your kids or you enjoy your lives more? That's an emphatic No. You are grumpy, angry and sad so you are needling and nagging him about tiny things (he didnt put the sellotape back etc). You are defending yourself by attacking him. It has become pathetic tit for tat. You are both behaving like arses, I think, albeit he is the worse of the two of you.
You need to sit down calmly and ask if he wants to fix this. Then you both need to talk, and be prepared to listen. You each need to learn how to listen without getting defensive or emotional, and use the conversation to find solutions. Counselling could honestly help you. I'm sure you're right that you landed yourself a miserable arse, but you had two kids with this guy and I'm sure you're not perfect either. The question is: if you could make things bearable again, would that be enough?
It has been for me. My kids are happy, they adore their daddy. I have a good career, great friends. I can won back my self esteem, and if I'm put down in public, I will calmly - and publicly - call my DH out on it, which makes him look like an arse and so, guess what, he doesnt do it so much. When he criticises me, I pull him up on it. When he belittled me or snaps at me for not doing something perfectly, i literally list for him all the things I've done perfectly that day and then sweetly ask him to have another go at providing a more balanced assessment of the my "error".
And in exchange when I do something that I know has annoyed him, I will acknowledge and try to find a way to avoid doing it again. In my house it is my DH who is the tidy freak, I don't understand it, but I've learned it is very important to him, and so for that reason alone, it has become important to me, but it is a joint enterprise and I have, after many years, got to a place where he will put up with a mess as long as I can say, "I'm busy doing Xyz, so I won't be able to tidy up until x o'clock" or "that desk area is going to be messy while I'm sorting through files, it will be like that for two weeks as I need to sort that area out properly and, unless you want to do it yourself, I need to create some mess there for a few weeks". So we've learned , we have BOTH learned, he needs to control his impulse to be horrid to me over things I consider trivial and instead he needs to gently and with love, explain why he needs something to be done a certain way. And then we discuss what is a reasonable way forward. So the kettle example it would be a non-issue for us now. He would say, "Penny I'm trying to save energy, because I think that's something that will save us money and be good for the environment. I can feel myself getting wound up when you fill the kettle because it seems like you aren't helping me save energy and that's important to me." Then I'd say, "oh I know it's important to you, I'm really trying but sometimes I forget. I'll try to remember but you can jog my memory if you notice im still boiling too much water but try and be patient with me, I'll get the hang of it. Actually this time though, I filled it that far for a reason (give reason). Would it help if I tell you whenever I'm boiling the kettle so you know what im doing with it?" To which he will usually say No, as being informed every time someone boils a kettle is absolutely bonkers but IF he says yes, then calmly do that for a while, without being facetious, until he just gets used to the fact that, guess what, you do know how much water to put in the kettle, you ARE conscious of it, you ARE trying to make him happy by not boiling more water than is necessary. Believe it or not this insane way of going on, has completely retained the way we treat each other. We are now friends who have respect and appreciation for each other. We notice when the other person is going out of their way to do things differently than they naturally would and we say thank you, or we reward them by going the extra mile and doing something to really cheer them up (I love it when my DH brings me a cup of tea and gives me a hug, he loves it when I tidy a drawer or sort out something that usually would fall to him).
We play to our strengths now and compensate each other's weaknesses, we are more of a team. We can call each other out on "bad" behaviour, without causing horrible atmospheres and arguments. We sometimes are even capable of noticing when we are contributing to making things get ugly again, and we step back, have a chat, apologise, move on.
We are happier, and we do have sex again, because we do get along better.
So for a start, You badly need some ground rules how to live together. What kind of crap example are you both setting to your kids right now? Grow up and sort out your problems, or leave. You need a conversation that goes, "there are some things that are really important to me, that you find difficult to do and arent important to you. And vice versa. So for the sake of harmony, let's each pick two things that need to change THIS WEEK." Choose Easy wins. You say, I am happy when the house is tidy so I'd like it if your shoes always go in the cupboard, and I get upset when i have to pick up after you, so let's agree that you always leave the dining table clear after an activity" Then he picks two things you have to change. You can gently negotiate if the thing he picks is impossible to deliver. The important thing is: you don't challenge the fact that each of you WANT this thing done a certain way. You accept that. But then you learn to compromise, and understand how much wiggle room you have. You learn to trade, "ok, I will try to nag you less and speak in a kind way, if you watch out for your anger when I don't do something in a way that you like."
You both need to agree that this won't suddenly be fine overnight, and there has been a lot of hurt and damage done, which has scarred your relationship pretty deep to the point you don't even want sex and really want to end it. If you want to climb back from that, it's a hard road. But if you DO want it, then commit to the work. And if frankly you can't be bothered, then call it quits, put your big girl pants on, and move out.
However you CAN learn to calmly respect each other boundaries, gently correct each other, learn what makes each other tick so you can anticipate what is likely to bother them and try to avoid doing that, and learn how to call a time-out when things are escalating and get tempers back under control so you don't spend days and days slowly winding each other up until you have a huge massive argument. That is no way to live.
Your decision OP. What do you want?