@wood Have you tried filing an injured spouse claim with the IRS? It's designed exactly for situations like this. Basically, this lets people who filed a joint return with a spouse (or ex-spouse) who had their refund garnished to get their half of the return. It's common when one spouse had unpaid child support, back taxes or federal student loans. You file Form 8379 with the IRS (available here: https://www.irs.gov/forms-pubs/about-form-8379) If your joint stimulus check was seized, I believe you could still get your half ($1,200) when you file your 2020 return. (Note that I think what you'd be looking for here is injured spouse, not innocent spouse. They're similar, but innocent spouse would be used if your spouse underreported income without your knowledge.)
It takes the IRS about 8-11 weeks to process the claim if you file online. Definitely file online vs. on paper to get faster results with the IRS (this is true at any time, but ESPECIALLY during COVID). If you're unable to resolve it, I'd suggest trying the Taxpayer Advocate Service. You may also have a free or low-cost tax clinic in your community. This is a tough situation, and I get why you're overwhelmed! But I think it's also a common one. I'm optimistic that you can resolve it without shelling out for an attorney. Good luck!
Has anyone here filed an injured spouse claim? If so, do you have any advice for Wendy?