((((((hugs you needed)))))
Your situation sounds very tough. I admire your honesty about your part in the disintegration.
It sounds like you both really need what he says he wants: fun. light-heartedness, closeness.
People might scoff at this, but it's worth a try. Google that experiment on the 33 or 34 questions you need to ask to get anyone to fall in love with anyone. Send it to him, and suggest a date with him where you ask and answer them and do that looking into each other's eyes thing somewhere the lighting is flattering and the setting is good.
It might sound like a trivial idea but when you're both worn down, that sort of easy to do silliness that is scientifically designed to bring you closer may be just what you need as a quick fix to start you feeling more positive about each other.
DH and I have had some seriously rough times. We got through them by remembering, often, out loud, sweet and funny things from when we were first together.
Can you go away for the weekend - not the pressure of sex and faking what neither of you feels, but to do something, some activity or visit some place you've both always wanted to see or do. Focus on liking and appreciating each other again. And focus on your own goals, maybe tiny ones at first to bring you back to a state where you feel more positive about yourself.
All the obvious stuff: exercise, fresh air, silly comedies, meditation, affirmations, CBT etc can help.
Suggest you give each other a month to both improve. be kind day by day, be silly and nice day by day. Flirt if you want to. Give yourself and eachother treats. See if after a month you feel better than you did. if you do, take another month and improve even more.
For you, you sound shattered and drained, and in dire need of some self-care. Take a look at some of those life sites online. Live Bold & Bloom is good at helping you get your buzz back.
Sorry this is long. I get depression and have all sorts of tricks to keep it at bay, so passed most of them on!