You're right to want to minimize your compulsive physical behavior in the workplace before it bothers your co-workers, but I hope very much you can also give yourself credit for the work you're already doing.

Don't let a friend make you feel publicly uncomfortable indefinitely just because they're probably a lesbian.

I'm of the opinion that it is always a kind and appropriate decision to get in touch with someone who's lost a loved one to remind them that you're thinking of them and have fond memories of the deceased.

Asexuality does not make our lives any worse or any better, we just face a different set of challenges than most sexual people.

If this is something you'd truly like to work on, not out of a sense of guilt but because you would enjoy occasionally reciprocating, there are a wealth of resources out there for the enthusiastic amateur (you are far from the only would-be blow-jobber whose spirit is willing but gag reflex is weak). You have more options than "no blow jobs, ever" and "regular whole-hog sessions to completion that result in vomiting."

It is so tempting to return rudeness with rudeness!

Acting politely in front of someone black and/or gay and then making horrible claims about their intelligence or worth as human beings after they leave the room is not kindness - it's hypocrisy.