tilly...that happened to me, I didn't know who my father was until I was 16yrs old.
It didn't bother me until I was about 50years old, but I knew that he was married and they couldn't have children and I was a "bone of contention" for his wife.
One Saturday night, I phoned him and it was clear that he didn't want to know. My wife was terribly upset, but I wasn't really bothered.
He died two years ago without having seen me or spoken to me Part from the short telephone call.
I would have liked to see him, but it was HIS loss.
Try and contact him.