First I developed a very painful lump under the skin on my cheek.  The day I got it I went to the urgent care because it became nickel size within a few hours and was painful through my entire head.  Urgent care prescribed bactrim.  After finishing 10 days of bactrim it still wasnt gone although was not as painful and had reduced to the size of a dime.  Now, one week later, just an hour ago I felt a sharp pain in my opposite armpit.  Its a little red and I can feel a large lump and it is extremely painful to move my arm or to touch the lump.  It showed up just as quickly out of nowhere as the first one on my cheek.  I have also had a twitch in my left eye or the last three months.  Not sure it any or all three of these symptoms are related.  Should I be going to the ER?
Yes! You have to see ER! The features you mentioned like pain, rapid swelling, tenderness all indicate simply an infective condition that must be taken care of and controlled immediately! Take care; regards!