Had really bad muscle tension from anxiety. My anxiety is gone now but today I have a sharp pain in my upper arm, like im being poked with a needle?

Breathing helps. Anxiety causes muscles to tighten. The brain is receiving an SOS and is getting ready to fight or flee. You can change that message by relaxing your thoughts using self hypnosis, or mindful meditation. Find a comfortable spot. Breathe deeply. Visualize a quiet, pleasant scene. Image a light, strong and healing flowing through your body. Let muscles relax as if little fists are letting go. Enjoy.
More information. There are many possibilities for this situation. If your muscular tension was in the same area, you may have injured the muscle. This may be the result of an injured nerve. Or, it may have nothing to do with the anxiety and muscle tension, but be of a different origin. If it is painful you may need to consult your doctor. If it is only annoying, monitor.