Confused About My Relationship

I've been dating my boyfriend for the last 4 years we are happy except in the times that we aren't: when we're fighting. We fight once a month over the smallest things, thankfully though, the fights don't last long. Everytime we have a bad fight, my boyfriend says he wants to break up and leave. I have a habit of not wanting to let him go, so recently I've decided that he should get space; I agree to what he says. He blocks me or asks me to block him.
I feel like I should wait it out, but I'm stressing over whether or not he is going to come back because there's no way for me to know..

I don't want to end this relationship.

The last time something like this happened, I didn't contact him for 4 days and on the 4th day, he messaged me and said he missed me and he wants the relationship.

Whenever I contact him, he tells me strongly that he won't come back again. But because of the past situations I can't help but not believe in the words he says when he's clearly still upset about the fight.

Every time he leaves, it feels like the last time, "the end" and I can't deal with that because I have too much hope.
He's always planning his future with me. His family is on great terms with me. He asks for my opinion whenever he's buying something for his house. He shares all his plans with me. I don't want to break up with him.

He has depression and anxiety, which somewhat explains why he withdraws from me, but it doesn't excuse it.
I have toxic behaviours too. Like I'm the one who always starts the fights because I'm a little impatient at times.
I want to change the bad in me, I put in effort, but I always relapse and it's never consistent. I lose my temper really quickly too.

I would appreciate any tips people have that they think might help my situation.
Thank you for reading through this.