My best suggestion is making the move on him first. Obviously has to be on good timing and when you can find the privacy. Start with being in a happy mood, flirting, small touches, ask for a kiss from him and when he does kiss you, get handsy? Put on some perfume or scented lotion to help him fall for the attraction. Men can get turned on pretty fast and might like that you are initiating it. Good luck as I’ve had a similar issue!
It sounds more like he has really low testosterone right now (and maybe even depression) and I’m wondering if he’s taking care of himself. If that’s the case it’s not much you can do, he’d need to take care of himself on his own- eat right, lots of protein, exercise, see the sun. Having a child can also lower their testosterone a bit but it seems more than that. Go out for a steak dinner and do something active/fun.
Forget making him feel good about himself. Get yourself a good vibrator and relieve that sexual tension - it will decrease the arguing too. You can then just have a nice celebration without you giving off any sexual vibes and just enjoying yourself. It might help him relax a bit.
Are you able to set aside special time where you can simply sit together, no distractions, no phones, and rebuild a foundation of intimacy about everything that has changed, struggles, hopes and things you’re grateful for and want to expand upon together? I feel like a lot of times when the physical side of intimacy falls off it usually starts with not connecting or feeling seen on an emotional and mental level. It something that always requires maintenance like weeding a garden and investing in growth. Once you both feel seen and heard and appreciated exactly how you are now that usually naturally leads to more physical intimacy.