I've lost friends for reasons related to my behavior and people's ignorance, and I've destroyed new friendships due to my behavior as well.

Had friends do that thing where as soon as you show symptoms, they decide it's contagious and head for the hills. Good riddance.

Had friends pull back in similar ways, and froze them out or burned bridges because I was burned by the kind of friends I just mentioned. Even though these ones were okay. Oops.

Had friends not understand my isolating and hiding when ill and/or take it personal and thus get angry or drift away.

Had new friendships just starting out where I went mixed/hypo and sent the other person running. Those are pretty acutely painful, though the friends I actually wanted who disappeared are what keeps me up at night sometimes.

I have one friend who ghosted me hard almost a decade ago and moved halfway across the country. No goodbye, no explanation, just cessation of contact and gone. I still think about her and wonder. I think her husband might be controlling and did not like it because we were somewhat close.

Nowadays I've been low and isolated so long that I'm pretty feral and am having to ease into learning how to act around people again (not disclose too much, not take over the conversation when I start to get charged from it [I cycle REALLY fast and interacting with people can get me hypo in minutes]). I'm doing this by volunteering at a place where almost everybody is non-typical in some way and thus you really have to work hard to stand out for being unusual. And also keeping up with a gaming night with a bunch of nerds who are also more accepting than many of being a bit odd, although they have been not too interested in me lately and I don't like the game much any more. Yesterday I decided instead of ruminating on it and wasting more effort on them, I will try to find another gaming group.