Suicidal

I don’t know, I’ve been watching a ton of videos that aren’t good for me, I feel ugly. I feel disappointed about everything in my life. I don’t tell anyone about it because I don’t want attention. I’m in therapy but last time I was honest I went to the hospital for weeks. I seriously don’t feel happy at all anymore. I’ve told my partner that I want to be with them “forever” when I feel so sure still that I’m going to end up killing myself. There’s times where I do feel happy but it rarely lasts long. I feel like they aren’t happy with me as much as they say they are. I found out that they were interested in someone else while we are in a relationship. They ended up just saying that they found the other person attractive and that I can’t control how they feel or who they are attracted to or like? Am I overreacting? I know that others have life much worse than me which is why I don’t tell my partner because it feels stupid? I hate being babied or feeling like it’s all pity. I just don’t want to keep feeling so much guilt for thinking like this? I feel selfish when I talk to my partner about our future when I feel like this? I don’t know.