As a child I was taught to have empathy for people and treat them the way I would want to be treated.
I should be the person I want to be.
I hide a lot of who I am, and make many of my "deep" parts of personality seem "normal". So most people just mistake me for a "normal" person.
I spend, have spent, will spend, many hours considering who I want as a friend. If I have PTSD, and triggers, then I simply want to know they will be there regardless. I chose my friends on that basis, and on the good I can see in them.
I don't always tell them/show them I have PTSD, and I learn to control it well.
If someone approaches me with a consideration of friendship, I let the moment continue, and carry on. If I don't like them, and I know I don't want them in my life, I do my best to be polite but let them know. One time I was so bold as to show my middle finger. She doesn't talk to me anymore and that pleases me. As rude as that might be, she really was a hollow person.
Be selective, pick your battles, and remember if you don't have a deity(mine is God), then you're you own best company.
Distraction is the key to the pain until you can find a community of people.