I Was Prescribed Tramadol Last December For Shoulder Pain (which,

I was prescribed Tramadol last December for shoulder pain (which, after seeing 7 different doctors and having multiple tests done, I still don't have a diagnosis for my pain)and still have a few pills left, because I had been giving various other meds to try for pain relief so I didn't finish all of the Tramadol. I am in a lot of pain today and am probably going to an urgent care facility tomorrow because I can't do my usual daily tasks when I'm in so much pain and none of the other doctors are helping me. I am also in the process of weening off of Cymbalta (I had been taking 60mg, now take 30mg for a few more days-then one every other day until they're gone). I've heard of serotonin syndrome, which is why I'm asking if I'd be at a huge risk of that if I took only 1 pill to get me through until tomorrow. My stomach can't tolerate ibuprofen and tylenol only helps if I take 5 or 6 extra strength ones, which I know isn't good either so I don't like to do that. I don't know what else to do...