I Had Spinal Fusion Surgery Back In 98. C5/C6 And

I had spinal fusion surgery back in 98. C5/C6 and C6/C7. Have had no issues. Moved in late August and did something to my neck...figured I just overdid it. Long story short, it's been hurting off/on since. Got worse late last week. Went to ER yesterday. Said I have a bone spur on C4. Gave me Tramadol, Prednisone and Methocarbamol--think she said it was muscle relaxer. Nothing has started working. I was prescribed Xanax (lowest dose and then I only take a half one occasionally--only twice since summer) just to help me get to sleep. I'm also on Crestor, Levoxyl, Metropolol, Sertraline and 81 mg aspirin daily. Question is....if it's been almost 6 hours since I took anything from the ER, can I take a half Xanax to go to sleep?