So 2 questions.

1) How do I stop thinking about and being angry at shit that happened ages ago?

In particular there's this one thing that happened over half a year ago where I had a bad falling out with a friend (we're no longer friends). I'm angry at him for how he fucked me over but I'm also angry at myself for how poorly I handled the situation in hindsight.

I know it's completely counterproductive and a waste of time to devote energy to thinking about shit that happened ages ago but it regularly keeps coming back and replaying in my mind.

2) How do I control my anger in general?

For example if I perceive myself as being treated unfairly, or if there's a situation where I feel like someone is trying to provoke me etc.

I've tried meditating, I've been finding it really difficult to get into but I'll persevere with it. I lift, and that definitely helps, but there are still those times when I'm in a low mood and the irrational anger comes back. I also intend to start reading more about stoicism.

I know anger is a sign of weak frame as well as being an unproductive emotion so I'd appreciate any advice. Thanks boys