Hi there. If the left side of your body was affected by the brain injury, it would be the right side of your brain that was injured. As many traumatic brain injuries (TBIs) are complex, this might be only one part of the brain affected, however. If you are several years out from your injury, there is little chance for further healing of the brain, but this does not mean you can't get better in terms of functionality. I would suggest you ask your family doctor for a referral to a TBI specialist, called a phsyiatrist (i.e. physical medicine and rehab specialist). Ask if you can be evaluated at a TBI center affiliated with an academic medical center (i.e. one with a medical school). These are the most up to date specialists, typically. They will take a team approach to evaluating your issues and addressing them one at a time.
You're welcome. Hope all works out for the best for you.