I'm failing to build friendships/relationships because I'm too scared to be vulnerable and open up to others.

Especially when it comes to my online interactions, I get too scared to reveal myself, and even if I do, it's generally too late when the other person has already lost interest.

This is mainly stemming from past trauma, and the fear of being outed/blackmailed by someone online.
For contexts, I'm a gay dude in my mid-20s living in a very homophobic environment, in India.