Employment Law Questions? Ask an Employment Lawyer.
Congratulations on your rehabilitation - that is extraordinarily difficult and something to be proud of.
Regarding your licensing - that is something you need to deal with in addition to, and outside of the pardon that you are seeking. Licensing bodies are permitted to look at past convictions (as well as past disciplinary actions) even if they have been set aside, pardoned, or expunged - as the purpose of the licensing exam is not punitive, but for "occupational restrictions" (I understand that the application may seem punitive, but the application is deemed sufficiently distinct that the licensing agency is entitled to review such conduct even after the act has been expunged, etc.).
Given the history that you have with your license - your best odds for getting your license back is to hire a very specific type of attorney to represent you. There are attorneys (not many of them, and they are usually located in state capitols), that represent professionals before licensing and administrative bodies (such as attorneys before the bar association, doctors before the medical board, nurses before the board of nursing, etc.). They often represent professionals before all, or multiple agencies (there is not a lot of difference in the procedure or basic underlying standards) but this type of representation is different from your basic civil litigation.
You can find these attorneys using the State and local Bar Association directories, or private directories such as www.AVVO.com; www.FindLaw.com; or www.Martindale.com (I personally find www.AVVO.com to be the most user friendly).