I (19, M) have severe self-esteem issues. Need some advice to fix my life.

Recently started listening to David Goggins, which does show me that there might be a way out to live a better life, but I'm still stuck.

Background: I've been bullied at school for most of my childhood and it has affected me a lot. My growth stopped at around 16, leaving me short at 5'7" and I now have lost a lot of hair and have prematurely grey hair as well. I have skinny arms and ladylike/feminine/small hands and arms which makes me feel weak as fuck. I was a bright kid at school (nerd-ish) and never focussed on any sports and health, and I heavily regret now. In short, I have a lot of insecurities about my height and my body, and not being masculine enough. Moreover, I'm not good looking by any means so that makes me feel like an incel. I feel very unworthy of any woman I see or meet in my daily life. I'm full of feelings of unworthiness of anybody's love/affection and I'm constantly seeking out for everybody's validation.

All of this happened to me without my control, so I now consider it to be my 'bad hand' and all I now want is to be a slightly less shitty version of myself, that's it.

I try to try to make myself fit and fix my habits, but I'm mentally too weak to do this. I see a picture of anybody online, or even if I see any guy in real life who is slightly better looking or taller or has female friends, my mind goes into the loop of feeling more shitty and unworthy of anything in life.
I have this habit of putting labels on everybody: "Goggins is tall, so he's meant to be masculine and strong", even though I know his story and what fucked up mindset he had while growing up.
Any advice would be helpful.

How do I take control of my mind, while my mind is not willing to leave any chance of acting against me and making me quit?