I have a horrible pain in my right trapezius/neck/upper back for the last 3 weeks and it is not getting better, what should I do? I've worked out 5 times a week for the last 6 years. 3 weeks ago all of a sudden I felt a horrible pain in my right trapezius

Get checked. If it is severe it could be a pinched nerve or herniated disc in your neck. If it is just pain and not numb/tingling then can try a chiropractor or massage therapy. If it persist more than a few days, see a spine specialist.
At . At this point, you should look into seeing an ortho doc, or perhaps a sports medicine physician for further medical imaging and/or they could even do injections into the area if needed. Oral meds are good, but have you tried topical nsaids or perhaps the flector patch (diclofenac)?