You are a competent successful person. You already have a good idea of how the terms are panning out. You need only to have it put on paper. Believe me, you can do this. Do keep it simple but do have it then reviewed by your attorney for strength.
With our product we wanted obviously to establish the basics:
* Who is the licensor?
* Who is the licensee?
* How much per unit?
* When the agreement expires
* The option for the manufacturer