I could agree with @worraLiberty but then we'd both be wrong
One of my favourite quotes Retroflex - thank you -raised a smile. 
I suppose you could also argue that you made a choice to travel on public transport knowing that you are at a higher risk of catching something contagious from people who are knowingly (and more often unknowingly) contagious at the time. Even if OP stayed at home, the bus will be full of germs anyway from people who don’t know they are contagious, cross contamination from contact with contagious people outside of the bus etc
I wouldn't argue tis as others have already done it - seems pointless to repeat what they've said.
I'm going to genuinely apologise for picking on you now - but I'm leaving my comments because I think you need them (and others). You really are the one who is being unreasonable.
If OP said "I'm not having my children vaccinated, and even though little Tarquin is covered with icy spots we're going on the bus to Quentin's birthday party", she would be being unreasonable. However to say "I've got a bad cold and I have to go to work or I won't get paid" - she isn't being unreasonable
She has bills, she may have children who would end up inc are if she fell behind with her mortgage - whatever - it is a COLD!
I know it's a lot more serious to you than to most of the population, but that can't be helped. It's just a fact of life, I'm afraid.
If everyone with a cold stopped off work, this country would grind to a halt in about three days . . .