I'm in the beginning of a potty training "boot camp" this weekend. This, after a month of potty training that began well but became a power struggle. My 3 year old is definitely strong willed and in a rebellious stage - not just with potty training, but also going to bed.
Anyway, I'm trying what a friend did. I have the sticker chart up. Every time she goes to the potty, she gets a sticker. Every two stickers, she gets to choose an item from our bag of "treasure." (She watches "Jake and the Neverland Pirates" so treasure is a big deal.)
I just picked up cheap kid things at Target - placemats, sticker books, playdoh, music CD, bubble bath, vitamins, etc. - wrapped all of them up and put them in a gift bag that is in the bathroom.
Today is only the first day and it's going great. However, I plan on doing this for the next three days, through Memorial Day, and then crossing my fingers that she's used to being in underwear all day long and going on the potty only by then. I'm going to tell her on Memorial Day that if she stays dry all day she can go to Target with me and pick out her own bicycle helmet (something I needed to buy her anyway and that she totally wants). I might do this with swim socks that I need to buy her anyway too.
Good luck and hang in there. I definitely would recommend backing off of potty training for a week or two (I stopped a week and a half ago in an effort to take the pressure off and be able to approach it positively again during this weekend bootcamp). The back off is more for your sanity and peace - you need a break too!