Hi M. -
I have a really sensitive stomach, and have always had a crazy gag reflex to go with it. It really is a "mind over matter" issue that you have to mentally work on in order to diminish it. On the medical side of things, taking a low dose anti-nausea pill everyday can help with the gag reflex alot, but on the downside, even a small does of anti-nausea can make you extremely tired (which is not something you need when raising two children!).
I do a mental relaxation exercise when I start to feel the gag coming on: I close my eyes, and focus on relaxing the muscles of my throat while taking slow, deep breaths. Block everything out that you can, most importantly the stimulus that is causing the gag relflex. Focus on the movement of your chest as you breath in and out deeply, taking air in through your nose, and out of your mouth. Try to mentally talk yourself into not being nauseated by what is nauseating you - tell yourself that it is all in your head, and that you have the control.
It works for me - sometimes - but know that you arent the only one out there! (if this is a question of oral sex, thats a completely different can of worms that is a little more difficult to deal with...LOL).
Feel free to message me!
K.