You are literally me! I normally go to the gym five times per week and I am very nervous about not being able to go for a while!
All my literature states to start again as a beginner when I return. I think I will see how I feel, definitely no heavy exercise until 6 weeks, but if I am up to it I would like to keep active as much as possible and perhaps do some light exercise before that time. I plan to work with my PT twice a week when I go back to get me back up to speed and keep me focused because I will probably have gained loads of weight and lost loads of muscle tone.
Let me know how you get on once you return, I would love to hear about your experience.