There are no meds to help with tinnitus (ringing ears). If the shaking hands are only when you are trying to hold them still or do fine work, there are relaxation skills you can try to learn. My hands will shake the more I try to make them not shake. If I relax, they stop or lessen in their shaking.

Your prior concussions did not cause your current symptoms. It was the fall at work that did. It may have been the straw that broke the camel's back but without it, you would be doing much better. This last concussion should not be a big deal because your 13th could have contributed to it with balance and coordination deficits. Either way, it sure sounds like number 13 was the life changing impact.