Obviously I do not fully know why you fell out with your family or why you are having little contact with friends now. But I have to stress to you just how important it is that you do not give up or lose yourself for the sake of a relationship. After all, he fell in love with that person. And I've seen it all too often, friends of mine who've practically tossed away great supportive friendships for their partners at the time. Then when it all came falling down they expect the friendships to just pick up where they left off. I'm not saying this is you. I'm just saying that, even if you've moved a distance, it's important to still keep touch with friends for them and yourself. Having other support networks beyond your significant other is vital in my opinion.
I don't know what to say about continuing or not continuing your relationship, though I do agree a list of pros v cons would be useful to at least help you to see what you may be giving up/gaining from this. You shouldn't have to walk on eggshells 24/7, let alone tread lightly on them. Relationships are about being yourself, about fully accepting one another, all in - flaws, quirks etc. If there's something you cannot bear about him or his ptsd, or vice versa, the relationship may never work.
I hope you figure this out and take care of yourself in all of this :hug: