Damn I'm lonely. I feel like an outsider in society.
I wish I could talk to people and not immediately regret it afterwards and fixate on how awful I think I did. It would make the whole "meet new people and maintain friendships" thing easier.
As a fellow outcast of society, I can relate. While I can't say I've overcome it, I can atleast offer my own perspective: I obviously don't know you Spehss, but I feel it's worthwhile to ask meta questions like "Why am I lonely?" "What is loneliness?" "What is the value and meaning of loneliness in a wider social context?" "Should I even feel bad for being alone?" "Is there any advantage to my state of loneliness?", etcetera and so on.
It's not me asking you these questions, it's me asking you to ask yourself these questions, so don't feel compelled to post any answers to us on these forums, though do if you feel it would help, but ruminate on the meta-perspective and take as much time as you need, as any sense of urgency may lead you to a false conclusion prematurely. Now, I'm actually asking a lot of you here, because taking an objective look at your own emotions is a very difficult thing to do, especially when you're mired in the quicksand-like mindset of depression or fatalism, but it's something that must be asked of you, as divorcing yourself from your own concerns is the first step towards true objectivity, and therefore another step towards the elucidation of your actual foundational concerns in life and the solutions thereof.
My initial judgment of your situation isn't "I'm bad at speaking to people", nor is it "I worry too much over-analyzing my conversations and therefore I don't extract the intrinsic enjoyment of social interaction.", I'd feel it's something closer to "My self-image or prior experiences in life impel this behavior of worrying and analyzing, and that if I find the root cause and work on that, then the symptoms of speaking or worrying will clear up of their own accord."
I'm not one to offer any advice that isn't useful, and as I'm not a professional in any capacity but a lifelong sadsack myself that lives in their own head, it may not be, but I feel that the solution to your worries lies in the realm of self-reflection and not simple exposure therapy as pisskop implies it is.