Getting divorced and don't have access to old Steam account

I've been trying to find a solution to my problem but have hit dead ends everywhere. My ex and I shared a Steam account which was linked to this EA account. I basically just played Sims 4 and the rest of the games belonged to my ex. In the grand scheme of things it isn't a big deal, but I had huge saves and can't afford to repurchase all the packs I had (my ex stole all of our joint savings when we separated and I don't know if I'll be able to get them back). I was able to set up family sharing with the old Steam account but apparently DLC aren't included in that so I can't just transfer my saves to the new Steam account I made. I've spent hours and hours trying to figure out if there's any option that will work and haven't found anything. Does anyone know what I could do? I'm so incredibly frustrated at how much money my partner cheating on me has cost me and it just seems to keep happening.