ghost of the past that dont let me move on

So i had been isolated for many years, i tend to be on my shell, and being really harsh to myself. I usually never go out, but with this friend i made in a mental hospital sometimes we go out, its kinda the only friend i can hang out with. I am 44 years by the way. So thing is i asked him to go to a nightclub with me, even though nightclubs are kinda a nightmare for me, I usually never speak to anyone i dont know in real life, having lots of people around me, and the most triggering part having women dressed up in desirable ways its super trigger for me, I got so defensive that almost angry in a way. So my friend told me to be less pretentious in what to aim for, I never could hook up with anyone in nightclubs. Although this was a nightmare for me, it really helps me to push myself outside of my comfort zone. One of the biggest issue why i have difficulties getting close to someone or talking, part of me is kinda bitter , resentful of being rejected so many times, it makes me feel useless and only lowers more my self steam, but not talking and isolating does not help either.