For me, the only thing that seems to work is blasting music in my ears or drawing the thoughts out. Even if it's just blobs of nothing. Most of my canvases are just black with white blobs and color streaking down in the sky. All I can say is writing them down or finding something to get them out there without them having a negative impact is the only thing. Even if they aren't the "violent" negative thoughts, any negative thought could be either ignored, talked about with someone you trust (a dog/pet, a pillow or stuffed animal, anything really). All I can say is it's really up to you on how you try to deal with them. Some tips may not work but try to not get in the habit of ticcing/twitching when it happens, it's a bad habit to break and it hurts (speaking from experience)

Changing your mindset is huge. Personally, I find it helpful to focus on things I look forward to rather than anything else. Find things you enjoy doing and set time aside for them, it makes a huge difference

Learn about cognitive distortions. Work on identifying when these thoughts occur, challenge them one by one. Over time it will have an impact on the way you think. But be patient, it takes time!!! Good luck!!! Let me know if I can help!