Ex friends are talking behind my back. Advice ?

Long story short, the friendship turned sour after an argument and he decided to cut the friendship and then I said I don't want to be friends anymore too. Connection was lost but I occasionally say hi to the members of the group that I havent had conflict with. For what its worth, the argument was lead to me getting insulted basically and he was attacking my character saying things like : i have low self-esteem, no confidence and i'm only looking for an apology because i want to bring him down to my level.

They share info to the other guys who I don't speak with anymore and they have been gossiping. For instance, I got a new job and only 1 out of 6 of them said congrats to me. I mentioned I was going on a date with this girl this weekend and asked if they know her to which they said "yeah we've heard about her but she's been with street dudes" and they started telling me how im "presentable" compared to what she usually goes out with.

They shared this info with the other guys and those guys laughed about it saying all kinds of things. Basically saying im going out with a s**t and how they didn't expect me to like that etc just stuff to put me down and they've been mentioning to others and saying im sensitive (also showing the arguments I had with them over text before the friendship ended).

What's the best way to handle this ?