Don't worry about your progress too much, it will come with time. My wife is a runner, I "was" a biker about 10 years ago. We both bought new road bikes for fitness and for a sport we could enjoy together. She was in much better shape then I was, but did not have the muscle development to ride a bike, though it was years for me, it came back very rapidly. She can out run me any day, but I can bike further and faster. Its different for everyone, but it will come on fast and strong, its only been about 6 months for us, and I feel like an animal on the bike compared to when we started. I've lost 15 pounds as well.

I don't know that I agree with riding 4-5 times a week when you start out, though you can progress to that point rapidly. The main thing to watch is your knees and your butt! It takes a good fit and time for your knees and butt to get used to the punishment. Just my opinion.

Scott