Your value as a human being isn't dependent on your coding ability. It sounds stupid and trite, but it's true. A lot of these types of insecurities arise because we allow things access to our self worth that we shouldn't. Letting other people's opinions affect your core self worth is like giving them root access to your computer and letting them write directly to /
And I think in this analogy having thick skin is kind of like a firewall, it'll keep things out, but it's often just security theatre.
It makes sense to give other people access to your computer. The world is boring as a singleplayer game, but how much access is the right amount? It's worth thinking deeply about where your self worth is stored and who and what in your life has r/w privileges.
Also, this may sound really out there, but if you don't have a good basis for self worth/self love, but if you can figure out the right way to frame it, consider asking your parents or other close friends why they love you. It's a very on the spot kind of question so don't put any value on if they don't answer, but I asked my mom that once when I was in a really dark place(and we don't have a very good relationship) and I was really blown away by her answer to the question. She straightforwardly listed all the positive qualities she admired in me and asking her that was probably one of the best decisions I ever made. It really improved our relationship and probably forever positively impacted my view of myself.