This feeling of loneliness is hard to fill. It takes time. I'm a pretty lonely person for other reasons, I go out and have friends but I find that there is too much noise in my mind and the moments of genuine connection are rare. I'm now reading books on chan (zen) and learning to cultivate and enjoy a more peaceful mind. I've finished therapy and been a psychiatric patient for years. Nothing worked until it did. It's constant education. I'm not claiming to be cured or healthy, but I'm happy. I can imagine how hard it is for you becoming so sudden.

There's definitely a lot of paths you can explore. There is therapy, philosophy, experiences. You can go to therapy to find answers. Even to find a first step. You can read any sort of books to find myriad new ways in which you could perceive the world and yourself in it. And the experiences come along the way. If you are taking the effort that is good. To take up effort you need to see the future. Seems like you believe in it, but wish to see it clearer. Just know that at the beginning of the path nothing is clear, but time is the only constant. And that every feeling is there to tell you something but you only need to recognize it. If it's still there trying to break through, let it through. With every move you make progress. Be kind to yourself.

Good luck my friend.