I think it is a natural reaction insomuch that homosexuality is not really accepted. More generally though, being different in whatever shape or form from the norm (e.g. colour, sexual orientation, religion, whatever) is viewed with 'suspicion'... Thus, being a minority so to speak is scary.

Hopefully, things are changing for the better and geared towards better acceptance levels (in terms of society/individuals etc).

Maybe you just need time to adjust if that makes sense. Don't be too hard on yourself...