I'm having trouble opening my mouth after getting shots from the dentist?

I can talk with no pain. However, after going to the dentist for a cavity filling, there is this pain in the back of my mouth in the area where he injected the shots, and it only hurts when I try to open my mouth wide. He had to give my THREE shots by the way (my tooth wasn't getting numb) This is very frustrating, especially when I try to eat. I can't even take a bite out of a krispy kreme doughnut! Anything I can do? The appointment was about 2 weeks ago.