It’s a difficult situation and I feel for you and your relative, truly. I’m at a loss for what to suggest in practical terms, though, besides look after and be kind to yourself. It might help if you could think of some healthy boundaries you could put round your relationships with your parents, as long as you can stick to them if/when they try and push against them. It’s ok if you can’t do that, though, sometimes reduced/no contact is the better, or only real option.