I'm going to refuse to kiss my fiance
Why would you not kiss your fiancee?
It's my body and I do whatever I want with it
That is true, but if you are engaged to someone, then the expectation is for you to be affectionate towards each other.
The thought of it makes me sick.
If the thought of kissing your fiancee makes you sick, then maybe they are not the one for you. You two should have a talk about if you are right for each other.