The difference between 750 and 1500 is enormous. Your improvement is good, but take it one step at a time 
1000 is a good goal. Try to collect all the fundamentals. The basic areas (in no particular order) are openings, strategy, tactics, and endgames. Being well rounded will help you improve. Other than that solve a lot of tactics puzzles.
I gained 150 in 2 weeks from trying to remember Hikarus openings subliminally and chess giant openings and traps tricks and all. Should it be easier to get to 1500 or so or am I learning a little slow. I’m trying get to 1000 right now and I get annoyed by platoing and having to trying different things to spice it up