Need advice on cutting off a friend

I think I need some advice with this. (tw for venting a bit) I want to cut off my best friend. We've been friends for a year, but starting from a few months ago they started hanging out with different people and got tired of comforting me (I was going through a breakup at the time and I'm still dealing with it). Eventually I found out that they started dating someone, posted indirects about what I was posting, and accused me of ghosting them. The reason they said that was because I didn't answer to their message saying how they we're hanging out with their friends when I was at my lowest. I was suicidal, jealous, and feeling tired. So I didn't reply to their message, because I felt like they were rubbing it in my face. But then all of this leaded to me waiting for their message and them waiting for my message, so it was a weird situation. I know I should be happy for them, and they used to tell me how I helped them a lot mentally but they also used my words against me saying that "you told me to take care of myself, look how wrong that makes me look". I feel like an asshole, and I think I should just disappear from their life. Our last interaction was a bit recent because I had a panic attack and I began blocking/removing them on everything. They eventually added me on discord, asking why I did that but once I opened discord their messages were gone, meaning they deleted it. After that I didn't say anything and nothing happened. I don't know what I should do. I feel so weak with all of this. I feel used and betrayed. My mother tells me it would be the best to block them but my dad tells me that I shouldn't do anything. I would appreciate some proper advice with this because I genuinely don't know what to do.