I just wanted to tell you I can relate to this.
I get so tired of the expectation and pressure people put on their peers to be in relationships.
You can find people who will accept you if you are gay, jobless, homeless, of any religious faith, with any physical or mental disease, transgendered, disabled, a criminal, or a drug user. Yet make the mistake of telling someone (or having them find out) that you are not in a relationship, and you are not trying to find a relationship, and you will be universally ostracized by everyone. You are labeled a freak and a loser and people whisper about whether you are gay or have mental problems. If you have other strange habits people may whisper about you being a pedophile or a murderer. All for choosing not to engage in the lifelong, exhausting, and largely unrewarding courtship dance.
I am so tired of being ostracized by friends, family, and co-workers about my lack of a dating life that I will not talk about my personal life to anyone outside of the internet. It's just not worth it. No one understands why I hate dating, how it destroys my self-confidence and leaves me feeling anxious and miserable. I would love to have a loving relationship, but I will never "date". It's simply awful. There has to be a better way! Yet the way other people treat me insinuates that there must be something horribly, horribly wrong with me.
I am female and people just "assume" I have a boyfriend or a husband, so I suppose it is a little easier for women than men. I have been at my current job for a while and no one has asked me yet. Yet they know I never talk about having a boyfriend or anything, so I think they just assume that it is not a topic that is up for discussion. Or they assume I'm a lesbian. I'm comfortable with either - anything that doesn't require me apologizing to people about MY life choices.
I won't put up with it anymore and I think you shouldn't either. You don't have to make a stink, but just make it clear under no uncertain terms that you will not tolerate being mocked for your choices. You are not less of a person because you don't have a girlfriend, you are not mentally ill, you are not pitiful or a source of amusement or sympathy for others. It's hard but if fewer people based their self worth on relationships and sex, we would have more happy people in the world. There is no point in quitting your job, because these people are everywhere and won't go away. The change has to come in how you perceive yourself.