I want to cut off good friends from my life.

Hello, this is serious. Ive (19f) have been friends with this girl (19f) for a few years, we met all the way back in school. 7th grade to be specific. And we’ve been friends ever since. She’s never really wronged me or anything, but recently I’ve had this urge to block her and our other friends that I’ve met through her. They’re all good. I don’t know why I’m like this, but even thinking about them makes me on the verge of throwing up. Please help, I don’t go to therapy and I don’t know who to speak to about this. I’m feeling so guilty, like anytime I think of blocking them, my palms sweat. And I can’t handle confrontation on an abnormal level, I cannot and will not say anything. They deserve better than me and I know it. I genuinely cannot talk about this to her especially because she has a very defensive personality and anger issues and I’m kind of scared of her. I don’t know why I feel this way, I don’t have any friends except them, which should make me grateful because people would kill to be surrounded by good friends who are there for you, but I don’t want anyone in my life. I feel alone mentally (not in a life endangering way). But I just feel like I’m not interested in this friendship anymore. I mean my whole life I’ve never had any long term friendships or anything. They’re all super short lived, because I either ruin it or I distance myself. This specific friendship though—I can’t continue anymore. Please please help.