Those who are not single by choice - what is the reason?

I kind of am by choice, and kind of not: I worry that I won't be a good partner, to the point that it becomes a self fulfilling prophecy.

I'm a cringey no self esteem loser who doesn't know how to act around women has zero game literally zero never even had a gf. My reason I tell everyone is because of the hours I work.

I have to be single by choice, it makes it sound less depressing.

I think most loners are single by choice