Blow Jobs

I really don't like giving blow jobs. Mostly because I don't know how to give them but also because the thought of it is gross. I gave one to my boyfriend but I feel I didn't pleasure him because he hasn't asked ever since. Truly I would like to learn maybe I would enjoy them more if I could do it right, and pleasure my boyfriend. I don't know, I have a bad gag reflex, I want to do good.