The reason I asked was because I'm wondering how realistic you're being in your expectations/hopes, and how willing you might be to move your life around enough to fit friends into it.
I think you're putting an awful lot of restrictions on this. They have to have PTSD is a huge restriction, then to add your uncertainty about being able to do things depending on your sleep and how you feel, I think you're bringing your chances down to almost zero. Especially when your starting point is that you don't like human nature.
To be honest, I don't think it's so much about finding a place or a group where you can meet people. I think it's about finding a way to accept the adjustments and effort that are needed for friendships.
If various things make the kind of socialising you want difficult, you will need to accept the difficulties or accept not socialising. I'm not sure how you see an alternative. I had terrible depression and insomnia in my 20s. I used to drag myself to appointments with friends because if I hadn't I don't think I'd have had any friends and I couldn't face that.
I think it would be good to think about it from a potential friend's point of view. There has to be a bit of give. It's also about them.
I understand wanting to spend time with people of a similar age, who are liberal and like nature. I don't understand why they have to have PTSD. I wonder if it's because you're thinking people with PTSD would be __________ (fill in the blank). I would suggest that if so, then the criteria is someone who would be ________, not PTSD. You might find people without PTSD who can be _______ and you might find people with PTSD who don't have the personality for it, or are too symptomatic.
I do think there's hope for you to make friends if you can change your expectations a bit. At the moment it sounds to me like you're making it too hard for anyone to get through and into your life.