I think many people get hung up on how to train, or what to train with, and forget that they have to simply do it. If you had the entire summer and didn't improve to where you want, you need to examine why?

i strongly suggest getting a very specific training plan, putting it on a calendar and checking off, recording in some way, each session. Having that sort of data lets you very quickly see at the end of a month, it the issue is the training plan, or your lack of following it, that's the issue.

if you just asked me, I would have believed I was riding 5000 miles over the summer, but if I go back to my logs, it's more like 3000. Everyone naturally believes they are training harder/more than they are.