I know I'm missing something and I don't know what

*offense

I didn't read this post because of the misuse of "you're," as that mistake caused me to suffer extremely painful (mentally, emotionally, and perhaps physically) convulsions for about twenty seconds.

Jokes aside, perhaps. Not to the degree I did when I had just learned how the "horse" and the "castle" moved, but occasionally, sure. That accounts for a low rating, but blatant, material-losing blunders don't account for losing against higher-rated players when I am making none.

ok.

Can you say Chessmaster?  After I completed the course of chessmaster on on the playstation 1 game about 10 years ago I went from nobody to somebody when it comes to playing chess.  Also I recommend chesstempo.com to do the tactics practice  http://chesstempo.com/chess-tactics.html

Remember if you try chess tempo tactics and you can't find the best move then you are below 1350 because I could find most of the solutions with that rating.  Hope that helps. 

You are making a mistake if you assume that your TT or Chess mentor rating should be similar to your game ratings. Don't know about the mentor but TT ratings in general tend to be higher (especially at the top) by several hundred points. I think your TT is more or less what one would expect from someone with your game ratings.

A good player doesn't necesarrily know anything about chess, he (or she) knows how to play good moves. 2 completely different things!

How many rows and columns are you seeing ? If the answer is not 8 for both, you're in trouble.

Dnot overdue the games you are playing

Study, study, study. Review, review, review. And don't be so hard on your self. Although you may not be seeing the difference in the quality of your play, other people are. You have improved tremendously over a very short period of time