From what I’ve learned from my own experience and from others on reddit before they shadowbanned me for no reason, you don’t overcome gangstalking. You can learn to not be bothered by them, but you can’t overcome them. As the becoming an evil person no idea. I definitely have, but that’s because I can see how sheepish society is, and how easy they believe gossip, and how they see what they want to see even if there isn’t actually anything there. I hate people now.

Therapy maybe?

realistically: probably see a psychiatrist, work with them to figure out an accurate diagnosis, may involve treatment like anti-psychotic medications

I actually had a similar problem. In my case, though, I just asked the leaders of my neighborhood‘s local gangs if they could please have their conversations somewhere else. Luckily for me, they were cool and seemed to understand, but I guess YMMV

Sort of a case-by-case thing but questions like this have led to productive discussions between me and my therapist. Hard to say more than that from where I’m sitting though, we all respond differently to different things.