How do you guys officially leave a relationship?

I’ve been with this guy for almost two years and I have so many trust issues with him and after last night he stayed out passed midnight without texting or anything and knows I have a problem with that 😔 we’ve been struggling a lot and overall I think it’s a toxic relationship, he’s been my best friend for four years and although I don’t want to leave and love him I can’t do it 😔 I’ve tried so so hard and I feel like he doesn’t respect me 😔 I don’t know how to officially leave because I go crawling back two days later, how do I leave? 😔 I’m so unhappy and I can’t do it but I always overthink and blame it on me 😔