I think you're on the right track. You may be guilty of over training a bit though. Ditto what was said about cadence. I would suggest that at least on your shorter rides you never get out of the small chainring. This will force easy spinning, which may feel a little funny, but you'll get used to the decreased resistance and higher cadence. Other than that............time. I got faster last year by riding in pacelines with people who were faster than me. Unfortunately I'm a little behind this year because of a wreck that kept me off the bike for 5-6 weeks, but that's ok. Hang in there, it will happen.