Am I the problem..?

I was in a trio and we got saperated after we went to college, we talked and made time for eachother but then it got to a point where I was the only one asking them to meet up or atleast voice call in the gc. They always said they were busy and yeah it gets busy I understand, but it gets to a point....
One time I asked her if we could just call casually and she said she had an assignment so I got kinda mad and asked her if she's ever gonna put an effort to meet up (context: she never made time for us even before college and didn't even try to hang out with me and the other person)
She said that I can think whatever I want
So I just said "ok if you're always busy I'll just gtfo" and blocked both of them on every single social media platform.
What frustrated me the most was that my ex, MY EX. texted me saying I should talk to them because they're not doing well. I actually left him on good terms and we were friends, he asked me and I told him CASUALLY that I'm not talking to them anymore and he does this shit. as much as I don't care I hate the fact he even has nicknames for my ex friends, like......
Idk I feel like the bad guy now I literally don't know what to do