I had the problem of skunky smelling armpits, and pubic area, too. I think I got it from my boyfriend, who had the same problem. I never did have it beore him. The smell was always worse on the right side armpit.
It's a stubborn yeast infection.
The only thing I found to work was a combination of two topical creams, both available without a prescription. Just go down to your corner drug store and buy a tube of miconazole nitrate vaginal cream for vaginal yeast infections, and a tube of Neosporin (store brand is called Trible Antibiotic and works fine, as well). Squeeze out a one inch ribbon of each one, mix them together, and spread a thin layer over the smelly area.
You will find that the odor goes away quickly. Apply twice a day for a week or so. You should have at least several weeks odor free. I have found I need to occasionally reapply the ointments. Neither one seems to work nearly as well as the combination. I have seen a dermatologist about this, and my home cure works much better than anything he gave me. He did confirm that it is a yeast infection, though.