My (24f) Bf (24m) are fighting over me texting a college friend

My boyfriend and I were together for 3 years.

A guy I had classes with in college reached out after 4+ years. We had a completely normal conversation about work, school, and life. Eventually he said we should grab a drink sometime to catch up, and I replied “sure,” but we never picked a day, time, or made any actual plans. Looking back, I know I shouldn’t have kept responding, and I understand why my boyfriend was hurt.

My boyfriend became convinced I was seeing this guy and even messaged him. The other guy later reached out asking why my boyfriend was contacting him. I told him that was my boyfriend, apologized for dragging him into it, said we shouldn’t be talking anymore, and blocked him.

My boyfriend said we were done, but since then he’s still contacted me to ask me to do his student loan payment (which I normally do), asked me to reach out to someone for something for his work, and told me he’s “very mad” at me.

I’m confused because if someone was truly 100% done, why would they keep reaching out? Is this normal after a breakup, or could it mean he’s still processing everything? I can’t help but feel he overreacted but nonetheless I still feel terrible.

Just looking for opinions