For what it's worth, Zoloft was awful for me and Wellbutrin might as well have been children's aspirin. I bounced through a lot of them; Celexa, Effexor and I've finally landed on Viibryd which works great for me. So it may be a matter of finding the right med.

And no, she doesn't have to wear a scarlet letter. But it seems like you guys have gotten into an "all or nothing" type of standoff. Until you can compromise on things I'm sure you'll continue to have friction. For example, you guys could let said cousin visit, but have specific boundaries or maybe she could let you not be involved with that part of the family. There are ways to address this situation that don't have to be "all-in", but I think the first step is getting your depression under control and then getting both on the same page again. It's not going to be easy (believe me, I went through a similar situation with my wife), but if you both pledge to put in the hard work you guys can get there.