Maybe you can watch some videos on YouTube, there are nice materials from GothamChess for players on different levels, where he is trying to explain how to think in order to win.
I'm 1400 - 1500 in puzzles but can't get past 500 in real matches.

You play almost nothing but Blitz. How do you expect to improve if you don't give yourself time to think? Play slow games to improve, and quick games for fun and to test your knowledge.
How much time do you spend on solving a tactics puzzle? How much time do you spend thinking on your move in a game? In a puzzle you know there is a tactic, in a game you do not know that, so you have to assume there is one. Therefore you have to think longer per move in a real game that the time you spend solving a puzzle.
I've been playing on this site for under a year but I've played a lot of games during that period (relative to the total amount of chess I've played in my lifetime). However, I can't figure out how to set myself up for success. I enjoy puzzles and find moderate success with them, and I've habitualized some of the key closing ideas that they try to beat into your head. However, I have no idea how to get there and the puzzle skillset is rarely useful to me.
What are some resources that will help someone like me train the areas that puzzles don't cover?