Timeshares are an interesting area of law. An attorney would need to review the paperwork to see if it can be voided. Another possibility is to do a deed-in-lieu with the timeshare essentially giving it back in exchange for a waiver of the deficiency or being released from what is owed. There is no attorney in the area that I know of that does timeshare foreclosures as a major part of their practice but they do come up from time to time in most practices handling foreclosures.
a consumer protection and/or real estate attorney is what you need. Florida has some specific laws on timesharing and the specialized advice you need is from one of these groups of people. a foreclosure lawyer could help too but would need to know more facts in order to give you good advice.
Unfortunately the avvo find lawyer feature does not specify lawyers specializing in timeshare matters, although they have to be out there, especially in Orlando. You may want to look for someone specializing in community association law in Orlando through the avvo feature. Some of the laws governing community associations and timeshares are similar. Chances are if you contact a few attorneys practicing in that area of the law, a few of them have some experience with timeshares. It would be nice if your lawyer was also versed in debt collection law as well. Timeshares can have deficiencies (meaning you owe more than the timeshare is worth). Like the other comment said, a deed in lieu with a deficiency waiver may be a good settlement to your case.