Since you have an attorney you should be discussing your concerns with that attorney. This site is not for you to second guess your attorney.
I provide a free 15 minute telephone consult for security deposit claims and eviction defense. No attorney-client relationship is created by answering questions in this public forum. If you wish to create an attorney-client relationship, you must contact me directly and sign a representation agreement. Answers are provided based on general ideas and an answer specific to your situation would require a review of all documents.
If the employer is willing to negotiate, most overtime cases can be resolved within a month or so. I would inquire of your attorney about the status and any response(s) from the employer, and specifically what paper he is waitin for from the former employer. If this doesn't solve your problem in terms of getting a response from your attorney, I would put my inquiry in writing. If that still doesn't work then you should contact an attorney or call The Florida Bar.
Typically, pre-suit discussions can take as little as a couple of weeks to as long as counsel wishes they go on. Once suit is filed and assuming your cousnsel pushes the case along, trial dates can vary from one to two years. Settlements are common in wage claims, but when the settle depends on the parties and their counsel. I also agree that you should be speaking with your counsel as to what is happening with your case.