Filing joint

Me and my husband got married in 2017 and he never filed jointly until this year. I signed everything and so did he. When we left the tax place he had to go to work and never came home that day. I found out he was cheating on me for over 8 months with a 18 yr old he's 27 btw. They have been together ever since we filed which was January 10. He's threatened me and told me he wasn't giving me the kids money I don't deserve shit. Btw I don't work he wanted me home to be a full time mom and he wanted to make all the income now I see why just to trap me. He abandoned me and my kids and comes when he feels like it for the kids. We are going to court next month for a divorce and I'm getting child support. But idk what to do about the income tax money I've never went thru this before with him we have two kids and he only gives me 1000 out of the 5000 is there any way I can fight this to get the money since we filed joint?