Have the workplace provide specific list of duties ( e.g., amount of weight to be lifted, number of hours on your feet, etc.). Your doctor can review it and see if you have any limitations. If so, you MAY qualify for "reasonable accommodation" for your disability (ADA law). You would have to request it from your employer, and submit your doctor's statement. Sometimes the employer is able to make the accommodation (all depends upon the size of the company and amount of accommodation needed). If there are no limitations, then go for it! You are not disabled for that particular job.

Your TBI is a dramatic, life-changing event and returning to everyday life will continue to be a challenge for you. I think a major part of your transition is part of what all of us are charged to do; educate others about our new reality, have face-to-face conversations with our employers about some of our immediate, work-related struggles and garner support and consideration in those areas where we continue to need help. If your employer is not willing or able to make concessions or accommodations, then you have a choice about moving on or challenging the status quo. Good luck in your journey and hang in there. The fact that you can even articulate your concerns in such a clear manner is a great starting point and should give you every good reason to be optimistic.