Jenninfer.....Relax....breath in, now let it out slowly. I know, I know how hard and annoying and frustrating this is. My lovely child was the same way.....she was potty trained off and on from 2 1/2 to nearly 4. You have to remember that this is a thing she will do at HER pace, not yours (so annoying since you are the Mom and know all about this stuff, right?) Her pace is her pace and you cannot predict it, change it (without lots of heartache, yelling and tears) or punish her (and yourself) for it. For better or worse, she is an indavidual and comparing her to others is not only unfair and scary for you, it is not realistic.
As hard as it is, keep it a pleasant experience, try to offer rewards, my daughter liked panties, so that was her reward (be careful...we now have 2 drawers full of undies! What was I thinking?) I always stayed encouraging (84.9 percent of the time...the other 15.1% was very ugly and got us nowhere but crying on the floor next to the toilet) and tried not to punish.
We used a timer...set for 20 minute intervalls (20 annoying minutes at a time) and when the timer dinged...we went to the potty...every time....Oh the horror! This takes the pressure and blame off of you both...the timer says pee, and the timer must be obeyed. I had everyone involved, Grandparents, babysitters, daddy, etc so that we were consistent. Eventually it moved to 30 minutes (which was slightly less awful for one whole day) and then to 45 (keeping in mind the multiple peeing in the morning, after meals and such) After a few months of this, we had moved on and she had accepted it...pooping took a little longer and involved me throwing away a sacred pair of My Little Pony panties in a moment that is far from my finest. But eventually that came online too.
I know it is disheartening, but it is not a reflection on you, or her smarts, it just is what it is and it WILL happen eventually. Until then, there is meditation and wine. Good luck Mommy...you can do it!