I'm in a similar situation. I avoid closeness with people myself and I push people away because of my defensive mechanisms, trust issues, and general desire to live in my head, have fun with my nerdy hobbies by myself, and build my home online resell business. I have a small amount of friends and plenty of people to talk to on the internet to stave off loneliness although part of me wishes I had some kind of love in my life.

While I'm unsure what to suggest because I haven't fully solved my own issues yet, I would say find a more introvert friendly way of meeting people such as finding people with similar interests and hobbies on a site such as meetup.com or finding a local event of some kind with like-minded people.

Other than that bit of advice, the only other thing that I can say is to find a decent therapist if you haven't already and seek to get help and improve yourself.