So, I am just going to say it. No one here can tell you the way to fix your floor. We can offer advice based on issues IN floors, but probably not entirely specific to YOUR floor. To get an idea of how to repair any substrate to allow for floor covering installation one really needs to develop and mental topographical map of said floor..... or i suppose a hard copy of one. Problem being you say something like X is high and Y is high, and we tell you to sand those, but we are all missing that there is in fact something low and X and Y are nominal and the like. Basically it goes a little like this, examine your entire substrate, determine a nominal height it is supposed to be and then do anything in your power to correct anything that is incorrect. There really are only two options. Fill or Sand.
You can sort this out.
If anyone was in your home, no one would hesitate to tell you exactly what to do, its just very hard over the interwebs. No matter what you do/think, do not listen to anyone who says self leveller is a good idea in this situation.