Search Results: how to catch a cheating boyfriend

So here's the story, my first girlfriend I cheated on and ended the relationship. The relationship was fine and all but I was childish. We didn't talk for a year or two but patched things up and became friends again. We remained in contact for a while and helped talk each other through some tough situations.

we ended up deciding that it wasn't healthy for her to console in me about her boyfriend problems, though I always tried to be unbiased when talking about it. Skip 6 months of no contact, I just moved back to the state I went to school with her and wanted to catch up. Turns out she was upset that I let 6 months pass without talking to her and she was in a bad area with her boyfriend because she cheated on him.

She went from being down to catch up to don't message me out of nowhere it seemed. I've tried to get a hold of her but I'm blocked on social media and possibly her phone (or she doesn't reply at least).

I don't spam her with love messages or anything, I just want to be friends again. I'm not looking for another chance in a relationship, she was a great friend and I regret letting go of that. So should I ask a mutual friend to talk to her for me or just forget about it?

TLDR: had good relationship that I ruined, turned to great friendship that I ended, now I regret it and want my friend back... should I try or leave it?