Am I going crazy?

Lorelei❤ • "she's a girl with bad habits and good intentions"💫
I need some advice right now! So I'm 18 years old and I've always been an anxious person but I started getting really negative thoughts. I used to have really bad ones, like hurting others, but I would never do that. I would cry every day because these thoughts were disgusting. It made me feel liken I was going crazy. I still get bad thoughts once in a while but not about hurting others (although I always feel bad that I used to have them). It's more of how I'm a terrible person, how my boyfriend's going to leave me for someone better (we've been together for almost 3 years and yet I get these thoughts), that my friends are just pretending to be my friends, and that I might go crazy. It's pretty scary. I really hope I'm not the only one that gets these thoughts. The worst part is that I can't always control my bad thoughts and I just end up crying and googling what's wrong with me and leaving me to the conclusion that I'm crazy. I really hope I'm not! Does anyone have any advice to give for these negative thoughts to go away? Thank you!😭😫❤️