Why do I feel sick in the shower?

Lately when I take a shower I feel so sick. It starts while I'm in the shower and I feel like I'm going to vomit. Today I had to hunch over because I was about to puke so I got out. I couldn't even finish getting all the soap out of my hair. I have to sit down and I'll still feel sick in my stomach but it passes eventually. Why could this be and anything to fix it? Thank you.