Fought with weight for years. Gastroenterologist finally put me on the Atkins diet and it did wonders for dropping weight. Riding is now a lot easier.
Don't know if your insurance will cover it, but if you can get into physical therapist with someone who understands cycling, your age/weight, and your goals they can work your leg and body to get it back into condition. If you like your physical therapist, they are doing something wrong! If you can go to PT, try and check with your local college Athletic Training department and see who they use. A PT who is used to working with athletes is much better than someone who just works on the general population. My PT rides MTB and is brutal on me when I need to go in.
If you don't, subscribe to something like Road Bike Action magazine. For me, looking at all the riding gets me excited to go out. I also try and ride with a group. They push me and keep an eye on me. More people = more fun!
You have the right mindset, now just move forward with it and keep going. I won't do an E-bike because I want the exercise, but I also don't do MTB, so you may need that extra if you go off road. Try the road for awhile until you are healthy, then go to the e-MTB.