How can I get over this fear of shots?

When I was younger, maybe 4-5, I wasn't scared at all. Now I'm twelve and deathly scared. The fear includes finger pricks, IVs, any needle thing sticking into me. I have to get some shots in two weeks, and the nurse refuses to let me get any anxiety pills (She thinks they are "excessive"....Pfft!) I cringe even thinking about shots. When I had to get a finger prick, I ran away to the bathroom for ten minutes. When I finally came back, two nurses and my dad had to hold me down while a third did the prick. It's really embarrassing and I wish I was okay, but....I'm not. Please advise.