Thanks. Your advice is welcome!
I just tried chess tempo, and that is a good site. I like how there are explanations on the side as what type of problem it is, such as fork, exposed king, etc. No, I don't know those definitions. I recognize a couple of them.
Consider the following two things carefully.
If you don't know, but only a few of those definitions, you are doing puzzles and playing games from almost nothing but your intuition and "raw" calculation ability.I think your ratings are actually pretty good considering.
I knew there was a reason you were attracted to this game. Given your raw ability, learning those definitions and practicing tactics will make your ratings probably go up 50 to 100%. You will have to get intimately familiar with opening theory and end games also, if you want to go any higher than that. Good luck.
I mostly practice tactics on chesstempo. I like that chesstempo has an "untimed" option (standard mode) so you can think as long as you like until you find the answer. Sometimes I spend an hour before I finally figure it out. I'm 2139 for standard (ranked 84/10745!) and 1802 for blitz on chesstempo.
I think one thing that helps is that you have to understand the threats and possibilities in the position BEFORE you start calculating specific lines.
Another thing that I think helps is, every once in a while I will go over the list of my last 100 problems and open whatever ones I got wrong in new tabs. Then I re-solve the ones I got wrong to make sure I learned them.