Hey there, gumm. It sounds like you're in a pretty complicated situation, and I'm gonna be honest with you right out of the gate: I don't have any easy answers. I know that social paranoia can be a devastating and traumatic thing to experience on a day to day basis, so I totally get why having friends and other human connections can be a source of anxiety in and of itself. It's as you say: if you have nobody, you have no one to lose, and nothing to 'ruin', so to speak.
But I'd like to ask you to take a minute and consider what might be feeding into that sense of paranoia? Off the top of my head, I can think of a few things. There's the risk of hurting someone, of causing emotional injury or harm in a moment of fear or anger when you need to lash out. There's a fear of being hated, of saying or doing the wrong thing in a way that results in another human being despising you. And, of course, there's that deeply uncomfortable feeling that comes with not knowing the right thing or how to say it, feeling judged or having expectations placed on you, or feeling like a fraud because you don't know how to hold up your end of the deal.
Or maybe you're worried about boundaries or space. For my part, sometimes I'm feeling social and want to interact with people, and sometimes I'm not. Having friends can mean either having to interact with them when you really don't feel like it, or having to find ways to tell them when you don't, which risks alienation. And if you do disappear for a time, there's always that guilt to contend with, the voice in your head that says you're a bad person for just dropping them and you'll just make things worse by trying to get back in contact again. It can sometimes seem easier to just not have any friends in the first place, and not have to deal with these feelings.
Problem is, that doesn't really work. You said it yourself: you've been there. You know what happens to people who are isolated and alone. We are social creatures, we need people. Even with all the complications they bring, and even when we don't want them, we need them. Our ability to connect to other human beings and interact with them, share our thoughts and our feelings, our struggles, it's the one thing that really makes us human.
But that doesn't mean you need to go out there and find somebody to hang out with and share your whole life's story, go on adventures on, see all the time. Those things are great, mind, but all we really need is someone who can understand us, or at least try to. Someone who'll have our back when we need them, pick up the phone when we call, tell us how bad it sucks when things are shitty. And, yes, occasionally call us out on our bullshit, because sometimes we need that too.
And for you in particular, you need someone you can trust. A person you don't constantly have to worry you're going to push away, or feel like they're judging you or expecting things from you. Someone who doesn't feed into that loop of anxiety that most social relationships can trap you in. And while i realize that you probably can't have that kind of trust for most people you meet out in the world, I feel like it would be easier for someone who knows about and understands your issues. The kind of person you could talk to about them instead of hiding them. Given the nature of this site and the sorts of people it attracts, I'm certain there are people here who fit the bill. Maybe see if you can find someone you don't have to worry about 'ruining' at the drop of a hat.
Moreover, let's talk about the anxiety itself a little bit. It seems like you're utterly terrified of the idea that you're going to do or say the wrong thing, and have your relationships blow up in your face. And I know that analyzing this feeling isn't going to make it go away. Our feelings just are, they don't typically ask for our permission, and we usually have to either justify them or fend them off after the fact. But even so, having some sense of how they operate can make them easier to handle.
There is an expression in my household, that both myself and my partner share and remind each other of often. It's called 'Rules for Other People'. It means that we tend to hold one set of rules for ourselves, and another for literally every other person in our world. For instance, someone else can say something hurtful, do something insensitive, or snap at you out of the blue, but as long as you can see your way around to where they're coming from and why they did it, you're probably okay. That probably isn't the case in every situation, but in general, I'd be willing to bet that you generally want to understand why people do what they do first and foremost, find a way to forgive, be okay with, or move past it first, and condemn, criticize, or place blame second. Most people, not all but most, operate like that. So you give them the grace to make mistakes, step out of line, or screw up, because people need the freedom to be able to do that. That's the rule, your rule for other people.
But not for you. For you, there's a different rule. You don't get to screw up. You don't get to say the wrong thing, step a toe out of line, or be problematic. Because then people will hate you, or judge you, or push you away and never want to speak to you again.
There's rules for other people. And then there's rules for you.
This doesn't solve the problem, but remembering it can help. It's worth considering what you expect of the people around you, what rules you apply to them and what kind of expectations you have of them. The way they're allowed to take up space and exist in the world. Those same rules have to apply to you to. You're not different. There isn't a flag or sign in your back saying 'punish me in particular, with great prejudice, for any social error I commit'. You need that space to be able to have foibles and struggles without feeling like your relationships are going to collapse in on you. And you need people who understand that you need that, and can help give it to you. Find them.
I don't know if any of this has helped at all, but I certainly hope so. Real, supportive human connections are precious. I hope you can find a way to not weaponize them against yourself.