You're in the war zone right now going kids is tough I thought my partner and I were as solid as any couple was going to be, our relationship has been tested to it's limit over the last 7 years (4 kids 7 and under) do you WANT to work at it? If you're already checked out it's not going to work if you have the desire to see it through and make it work you need to put in the serious work that may be required, do you get much alone time as a couple? Much support? You need to open communication right up air any and all the issues, start dating each other again be people outside of parents
Sorry you are having a hard time 💗 Have you tried counselling/therapy? Sometimes talking to a neutral third party can help. You could go separately and/or together. I hope you have a support network to help with childcare and chores so that you get a break physically as well as mentally. Are you doing anything for yourself? Like postnatal massage or getting your hair/nails done or taking yourself out for coffee/lunch?