If you are doing systems for M2, I would suggest reading the Constanzo Physiology textbook and watching the Boards+Beyond/Pathoma/Sketchy video at increased speed and then do USMLE RX flashcards or Zanki after each phys or path section. I think RX is a little better than zanki because it has less cards so you can do more practice questions. Definitely do all the Kaplan questions before each exam, but also another qbank, either Pastest before Kaplan or RX after.
It's just like a race to see who can do the most practice questions and read all the explanations. Then in dedicated you can take your time with Uworld and get a 240-250+. I think having the mentality that your score depends only on the number of questions you do is very helpful. Everything else is just there to help you get to the questions, you don't want to get hung up on the other stuff. Just my two cents, you can take it with a grain of salt.
For the rest of the summer, the best thing would be to start the RX or Zanki flashcards for the stuff you did in M1 and do all the pastest or Kaplan questions for your M1 material. If you can have those two resources completed for your M1 material before school starts up again you will have a very successful foundation.
Being one block ahead of your school in the videos/book/flashcards really helps. Then you can use the questions as your sole method of studying the current material, which is the probably the best way to study. And you can be watching videos/books/flashcards for the next block to always be one block ahead. It takes discipline, but not impossible. I think the most important thing is to study in a way that is FUN for you. You should really enjoy studying, because you will want to eventually be studying 10-12 hours a day, good luck!