I would tell your doctor what is going on and ask him what side for the meds that he is on. Like you said if it just started after his injection, it's very possible that be could causing it. But don't take what I say, did to get to the doctor and let him see what is causing it.
Had My Brain surgery, and I was so scared, but the doctors made me feel good and and I did. They kidded with me before the surgery and before I knew it I was in recovery Thanks for helping me. Mine is on the left temporal lobe. They say it is deep it my brain.