I can really relate to this. I have been alone for many years and I felt that I lost whatever personality I did have. Recent events have shown that I still have the same personality, just a much older version of it. I think I have definitely gotten a few weird quirks from the isolation but they are not too off-putting, I don't think.
As for how you are perceived, I don't think anyone knows most of the time. I don't think it is a big concern how one is perceived unless quirks scare people or can be damaging to yourself in some way.
Most people are irritating, I think that is a universal feeling.
__________________
PDD with Psychotic Features, GAD, Cluster C personality traits - No meds, except a weekly ketamine infusion