I usually just read posts, never bothering to reply. But I felt like I should, since I can relate to what you're feeling/felt. I too, am a vegan, and have felt, if only briefly, complete and utter social isolation.
I went through a period about two years ago in the summer when I was completely depressed and talked to no one. I understand what you mean when you say you feel like you've gotten colder and harder. I used to have mental breakdowns and I would just completely shut myself down. I would feel absolutely no emotion or show any emotion. It felt like I was just a void. I'm still not sure what exactly triggered that summer of complete misery, but it took over a year to recover from it. During the recovery period I still had "sociopathic moments" as I call them. Over time, I started to learn that they were more of a defense mechanism than anything. I would put my emotions out there, get hurt or feel threatened, and then I would withdraw into myself. It was a completely vicious cycle. I used to wish that I could feel nothing to numb whatever pain I was feeling. I've come to realize that this sociopathic state that I go into is more harmful than just feeling the emotions.
As for advice, it's hard to say what I did to get myself out of this prolonged emotional rut. I think it was a combination of moving houses, settling, and finally finding my place. By my place, I don't mean physical place. I mean mentally. And I know, this may sound extremely cliche but I have no other idea how to say this. I had to find myself and my purpose, and accept my situation and who I was. Before that, my mind was constantly in an emotional war that just got more and more damaging over time. I know how badly it sucks, and how life seems to be awful, but it gets a lot better. MUCH better. I can't even stress how important that is.
Based on what you've written, what's blocking you from being at peace is the social aspect of your past. I know that it seems so much easier just to block people out, and that being near people is too painful, but that is just because you believe it's painful. I've been there, done that, and it doesn't work. Humans are social animals and we're meant to be around others and be constantly socializing. I've noticed that a huge part of socializing is confidence. If you work on your mentality and building your confidence, trust me when I say making friends will be extremely easy. As an empath, we are able to read and understand people better, which is so crucial when it comes to social interactions. Just think about it this way: you have a natural advantage.
As for your families religious conflict with your sexuality, it can be tough for people to accept someone when they have such strong beliefs. But people can become accepting, it just takes time and effort on both sides.
I apologize if the reply is a bit long, and I hope this helps, even by a bit.
Sounds to me your a very old soul....I'm an old soul too...I believe I've lived many lives,,, with various tragic outcomes...I've been stabbed to death many times...hung...been killed helping people...I went through childhood not knowing what I should do... what I was good at...I was taken from my brothers and sisters...from my culture...and placed with people who loved me in their own way but couldn't give me what I needed... I lost so much...I continue learning through my lost culture and my ancestors...I don't feel I belong here on earth....I feel more comfortable and safe with the spirit world than I do with human beings...my abilities give me what I need to thrive and survive this life and world....being an empath is who i am and what i'm meant to be and do...as well as driving a bus...lol...you love to write and that's a wonderful gift...learning about your empathic abilities might just give you the tools you need to help you in your journey through this life....and fill some of your emptiness...