I know how you feel, being the "therapist" friend feels like being a mom picking up other people's laundry for them while they ignore yours and continue throwing more your way

They may not know what to do or perhaps it's a lot on them at once from someone who usually doesn't talk about their issues. Tryna give the best case scenario- Maybe you need another friend. Not saying to drop this one but the friendship sounds uneven and they might not've expected you to have problems you want to address like that. I think maybe with the next friend you get you should set the mood with your real self as soon as possible. Not overwhelm them at the start or anything, just start small, show you can be more than just content all the time. You deserve the comfort of someone to rely on just like everyone else you were kind to don't doubt that.