I should have left him a long time ago

I (19m) just left my bf, B(26m) of 3 months. I honestly should have left him earlier. Last month, I was at his place and he found my (now deleted) Reddit username, and I remember telling B not to look at my account, and he PROMISED he wouldn't.

The reason I didn't want him looking into my reddit as I had some post about me still having feelings for one of my ex's, I posted this post a week before B and I became bf and gf and I also a week before B found my Reddit, I posted about apologising to my that same ex, for posting his pictures on Grindr 5 months ago, the apology was made in December.

That morning, B was ready to go to work, and I went to hug him and wish him a good day at work, and he went, "I went through your Reddit account, what are you doing still talking to your ex?"

I never spoke to this ex before I posted his pictures on Grindr and the only time I messaged him was to apologise, and only to apologise, and this ex only seen the apology and has not replied back. I explained this to B and he said that "the intention was still there." MY INTENTION WAS TO APOLOGISE.

That day, I was ready to leave him, I literally was packing up stuff, and ready to call and uber home. The reason I stayed, was because B's roommate came over, I didn't want to deal with her, I called him to get to the house, he did, I got into the car and told him to drive, and we just drove around town until the roommate left. And we agreed to stay together.

The second incident was when I got a notification about his Valentine's Day gifts and hid it. B asked me what it was, I told him it was about his Valentine's Day gifts... For some reason he thought I was cheating. It ended in a screaming fight, then talked it out.

Now today, the last straw, last night, I booked a room for 2 in another city where my Dad lives, cause I wanted to see him. And today, he messaged me to cancel that booking so we can use that money to put towards our Valentine's Day trip. And the moment I told him that I cancelled that booking, he says, "so this is it? We're breaking?"

I was confused, he said that all day, I was on my Nintendo Switch all day (I purchased the Hello Kitty Minecraft world and the Hello kitty island adventure game for my Nintendo Switch and played them to see what the are like and I lost track of time) and I told him sorry. But it wasn't enough, and tried to spin himself into being the victim and started guilt tripping me by saying, "I was really looking forward to seeing you this weekend."

All the sympathy I had for him just evaporated. I told him that he put me under the impression, if I cancelled the booking we'll put the money towards our Valentine's Day trip. I just told him that he did this to himself and that I did not hurt him, he hurt himself and told him to never come over again.

He continued to guilt trip me and has threatened suicide, and I told him, if he threatens kill himself again, I'll call the police. Now he is begging, for me to get back with him, not to leave him, he won't stop calling, and I am like fuck off and blocked him... He had it coming and I should have done it last month. I'm fucking done with him, I messaged all of my family members that if he tries to contact them, to block him immediately.