I'm alone for most of the time but I'm one of those people who actually thrive on that, rather than go insane, and I really mean that; it seems to actually be "good for me." My mental health improves when I don't have to deal directly with anyone. I'm perfectly happy when it so happens that my work week features none of my clients actually around and I can just get on with my job undhindered, and unstressed by awkward conversations with people whom I can't fully be myself around in order to preserve the professional distance. It's just better without contact.
Then I do go out into the world for shopping and for my particular hobby, and there are interactions, but I don't have actual friendships where I see someone deliberately and spend time with them, and I don't have a relationship, and I live alone -- and I really like it! I love living alone, I'm the boss of my own world once I close that front door.
At one period of time I had a long break from work while resettling location, and there were a couple of weeks at a time in which I didn't even leave my apartment. I loved it. I have had intensely socially-busy times in my life and managed to enjoy them, but they've also caused ALL of the fcked-up events and traumas in my life too.
Just because we are social animals as part of the ape family, doesn't mean certain individual outliers can't be healthy and happy naturally differing from the norm. Apes might suffer consequences of isolating from the group, and plenty of humans may too, but I believe some humans don't always.
It's having to deal with people that fcks me up, not being alone, which heals me.