Advice needed!!

So my bf has never cheated on me or anything but I’ve been having a lot of anxiety and worrying about him cheating, lying, not wanting to be with me, etc. The crazy thing is that he’s a terrific bf and hasn’t done me wrong and we’ve been together almost 2 years. I didn’t have any worries or anything up until a few months ago. Idk why I’m having these thoughts but they really make me mad bc I have no reason to think them. I just see all kinds of stories and such on social media and tv where the other person has no idea and they get hurt and ig that’s what puts these thoughts into my head bc it makes me think like “am I being done this way?” I’ve talked to him about it and he tells me to just trust him and have faith and he’s always telling me that he won’t do me wrong and won’t cheat and stuff and I really do believe him so I just want these thoughts gone. It’s so frustrating when I believe and trust him 100% and nothing bad is going on but my brain just wants to think negatively. I worry about everything going wrong so it’s more of a me problem. It’s not even about HIM really, it’s all in my head so that’s why I just need to get rid of these thoughts bc it’s messing me up. Is there any girls who’ve had this issue and if so, help a girl out please!!!