Sorry to hear about this. I feel like I can very well relate. I'm older than you are and when I was in my 30s and 40s, I felt very much the same. I hadn't been married, though I came close a couple of times and did not have many relationships and friends. Also, it seemed like everyone else was doing better than me with their occupations.
Right now in my life, things haven't changed much since then, but I feel more content. It seems like now, "making it" isn't so important like it used to be. I'm still not married and only have one friend who is just alright but not great. Also my family has separated and there's very little contact with them.
My father passed away when I was in my early 40s and I got a small inheritance. When I received it, I decided to sink most of it into a down payment for a condo. When my mother passed away eight years later, I received more in the inheritance. A few years later I paid off the mortgage. A couple of years ago, I sold the condo and received three times more than what I purchased it for. So now I have the money in my savings and looking forward to retiring, which should be fairly soon.
I have been introverted and felt like an outcast all of my life; and have not been rewarded greatly because of it. I can't offer any suggestions but I had tried everything other people had suggested for me that would help, and nothing worked. Maybe I'm not much help, but at least you're not alone and I think that things can get better for you in the future.