In therapy I learned to assign the voices in my head to 4 different types of “people”: a sad child (fostering all those hurting emotions like sadness and loneliness), a happy child (that makes me feel bliss if I let it), a demanding / mean adult (the source of the negative self talk) and a friendly balanced one (the one who should actually do the talking).
Then I realized that most of the time the demanding and mean part is talking, telling me I’m not doing enough and people can’t like me the way I am. So we started working on trying to mute this part and giving a voice to the others.

E.g. the friendly / balanced adult it talking to me the way I try to talk to friends when they are not good.
Or when I’m sad I assign this feeling to the child and try to handle it the way I would handle a sad child and not how I handled myself in the past (it’s not that bad, others can handle it too, stop being so pathetic…).

It’s a lot of listening and questioning your negative self talk. To get started with this it helps to have an outsider you can talk about your negative self talk with, so they can help you build that positive voice in your head. Sometimes my therapist just said stuff like “that’s just plain wrong” (like when I told her that I’m at a better place in my life than the rest of my family is just pure luck and I felt bad for not actually deserving to have a better life) when I told her about my thoughts and it helped a lot.

Criticize the critical voice right back.

“Hey, brain, if you’re gonna make a diss track about me, learn to rhyme better. Your rhymes suck. I mean seriously, ‘incel’ and ‘Metamucil’? Dude. ‘Pencil’ was right there. Or ‘skin cell’. Hey, that could even be a pun, like, you’re gonna be an incel, dick like a pencil, trapped in the hell of a thin-skinned skin cell. Come on, do better.”

I found that meditation and yoga helped. During workout videos the instructor often says stuff like “You are strong, you are doing great. It’s okay if your pose looks different from mine.” While it may not adress your personal issues directly it helps viewing yourself in a more positive light.

Also meditation is a lot about realising you had a thought, notice that thought and allow it to move on. You noticing your feelings and allowing them to be.

These will be difficult at first, so try to keep at it for some time. If you see benefits - great. If not, that’s great, too.

Lastly, I find it important to add, that these practices can help but can’t replace therapy. If you feel you’d benefit from therapy, please do not let this deterr you from seeking professional help. All the best.

You listen to your self talk. When you recognize a bad thing, you say no, that’s not true. The truth is: xyz

And you need to say this xyz thing very explicitly to yourself, maybe repeat it, maybe say it loud and clear.

Search the internet for CBT, apply it to your negative self talk when you identify it.