You've got to change up the reward. The one your using is not working so try stickers on a calendar that she gets to put on each time she goes potty and at 5 stickers she get a BIG TREAT.
Or a different type of sucker that she has never seen, or let her play with your cell phone that you never let her touch. Something that will make going potty the coolest thing ever and when she does go, PARTY PARTY PARTY, call grandma, have your daughter tell grandma what she did, blow up balloons, get some horns, dance around the room, but make it fun.
I agree that you don't want the tantrums to rule the roost, but this is the one thing you can't fight and you can't make her do. She has to "want it" and you have to get creative to get her there. Remember that if a sucker worked on Tuesday, it may not on Thursday, time to think of something else. Since she is throwing fits now, I would drop the subject, leave it alone for a few days while you buy all the new treats and start over fresh and if she throws a fit, say "OK, I guess Mommy will eat this cool new Barbie sucker I bought for big girls who go potty" and watch that girl RUN to the potty, if not, try again tomorrow with something new. Remember don't physically push, sneaky around the back "mommy" push.
Good luck, and keep a box of baking soda handy for those accidents on the carpet and remember, this too shall pass.
BTW, We are potty training our second child right now, she's two and a half, we are almost there, not quite, but she's doing much better each week. Also, if your daughter goes to Mother's Day Out or a daycare or a church, find someone, a cousin, a friend, anyone who is potty trained that she loves to play with and use them to help you. "Macy wears panties, she's such a big girl" Right now my daughter doesn't wear pull-ups to Mother Day Out because her best friend Macy wears panties. I love when other kids potty train mine LOL :)