I have been having evening anxiety, feeling of doom, fear, is this from my pain med? I am currently taking Tizanidine and Hydrocodone/acetaminophen for neck pain. I take these every six hours at 6:00 am, 12:00 and 6:00 pm. This really sucks having pain after having C4-7 done in Dec. and new pain since March and has gotten so back I am on disability until they can find the cause. Has anyone had anxiety? I don't get it every day but when it does happen I hate this feeling.