Bridle Issues! Please Help!?

I'm having some problems putting the bridle on my horse. She was lame and on stall rest all winter and could not be ridden but now that she is sound and is able to be ridden she is having issues with her bridle. She wont let me put it on her, she throws her head in the air and starts to back up. She's 17hh and I'm really small so the only way I can get it on is when she backs up into a corner and I put a stool next to her and stand on it. With show season coming up soon I'm hoping she will get over this before I take her off property. If you have any ideas please let me know. Thank you