I'm Not Improving!

Despite what I do, my USCF rating won't go above 1400! People have told me to study tactics and it will help, but the truth is the Qxh7 sac never appears in my games, so tactics don't help that much. Endgames are also helpful to learn, people say, but with equal material, it is too hard to win. In books the positions are often exgagerated, with one king on e5 and the other on h8. "See, the active king wins!" they say. But in real games the battle is much closer, a king on e3 and a king on e6.

I think the real problem is that I'm bad at strategy. The general rules always contradict themselves, and I don't know which rule to follow! For example, "The way to beat a knight is to take all their squares away." Then later I find out I have ruined my pawn structure in an attempt to do so.

Another thing is that after the opening, all my pieces are on their best squares, so now I say to myself, what do I do? I don't think about position and stuff, like, restrict his bishop or gain some space. The first thing that comes to mind is "ATTACK!" These always fail.

So, how do I win games? Help is greatly appreciated!