Long term relationship breakup

I’ve been with my current boyfriend for one and a half years but recently I’ve just felt stuck and unhappy in the relationship. I don’t know if it was something he did that put me off (he’s been very clingy for the past month which I expressed that I didn’t like), he would also get upset if I didn’t answer his text for an hour even if I said my phone was away, he checked my snap score to see if it was going up to see if I was “ignoring him”, and just in general he’s very dependent on me which I can’t do.

In the past month especially, other guys have caught my attention and I obviously didn’t act on any of those feelings but it made me realize that maybe I fell out of love with my boyfriend.

I know I’m going to have to break up with him soon but I don’t know if there will ever be a right moment. He also suffers from anxiety, depression and a few other things and has self harmed in the past.

I’m so extremely terrified of losing him, losing the relationship I built with his family, having him freak out or resort to his old bad habits. My mind is all over the place and I can’t focus on exactly what to say or when to do it.

How should I break this all to him? Do I wait until things start to get slightly better with us or do I do it now even though we’re both hurting right now? I don’t know how much longer I can stay in the relationship but I don’t want to imagine the pain on his face or the pain I have to go through to get past this relationship. Please help or tell me your stories if you have been in a similar situation.