Started studying opening theory.

You are winning only 41 percent of your blitz games, overall.

Consider G/15, or at least add a 5 second bonus to your blitz games.

Studying many openings, and playing at that speed will probably not do much for your playing strength.  And apparently, it isn't helping.

But if you're not going to slow down your game to "slower blitz" or even Standard Chess, why even bother studying openings at all?

Your last few games with white were Colle-Zukertort, but it looks like you need middlegame work.  Try Johan Hellsten, Mastering Chess Strategy (2010).  Lot's of bite-sized exercises to strenghten your middlegame play.

Just glancing at your last 5-10 games, it seems you wait too long to castle.  That's usually the sign of a blitz junkie.  Not that there is anything wrong with that, but studying (many) openings and playing mostly blitz is probably spreading yourself too thin.

A five second bonus will (most likely) improve your G/5 play as well.  But you could also consider playing Game in 10/5, and make sure to use the "extra time" to calculate more in your middle game and endgame play.

Openings for players under USCF 2000, and certainly under USCF 1800, really don't matter much.  The "best opening" is one you know and your opponent doesn't.  All you really want from an opening is smooth development, a level position, and some familiarity with the resulting middlegame themes.  Better to know a couple of openings well, than a bunch of openings superficially.

IMHO, it's endgame knowledge that wins most games, and it works especially well at high speeds.  That's another reason for adding that 5 second bonus to whatever speeds you are playing.  Then you will almost always reach the end of the game "on the board," instead of the clock.

I stopped studying openings twenty years ago. i do not own any opening books I gave them all away years ago.

I play 1 g3 as white and 1 g6 as black and seek to get generic positions that I am comfortable with and understand.

My rating is 176 ECf I dont know what that is in ELO or USCF nor do i particularly care.

Same with me and opening study.  Never spend more than 10 percent of my study time reviewing openings.  With Black I also play the Modern Defense (with c6) against everything.  With White I play a Reversed Slav (or a Reversed Modern), against everything.

I practice both openings at relatively high speeds, Game in 10/5 and Game in 15/5.  It's great fun, and you can only become stronger, albeit slowly.

But the endgame rocks.  John Nunn's four new books (one on the Middlegame) are all outstanding.  Can't wait to study them intensely.  I love rolling my opponents at high speeds, in simple, tactical, endgame postions.

I believe 176 ECF is around USCF 2100 or higher.  That's the 97th percentile of active tournament players in the USCF.  Very strong player.  

I wish I had all the money back that I spent on books.  Some were quite helpful esp. by my fav chess author - Bruce Pandolfini - but to me the most help I ever got was from a hand-held chess computer that I got back in the late 70's.  In my 50 yrs of playing, I've never had any formal lessons - just experience.  Never got too far, but oh well, easy come-easy go.  That's me.

I think the conversion formula for ECF to FIDE is approx. (ECF*8)+650 making 176 equal to 2058 FIDE and about 75-100 points higher than that USCF.

On topic: I actually found the same thing to a degree. I started looking at some opening stuff about 6 months ago. In the beginning, I was playing the moves, then had no idea about the different ways to proceed after my knowledge ran out, found myself in situations I had no clue in. Needless to say, this isn't a good idea. If you're gonna study, study openings only part of the time. Make sure you know the ideas and ways to go after the opening is over. And still study non-opening-related stuff during the majority of your time, I would guess.

Some very helpful feedback guys, however, the question still remains as to how I can no longer beat the people I was beating before. It's completely illogical and nonsensical.

Well, I've seen this same thing happening often enough with my playing, so here's my two cents on the matter.

When you have only a basic opening knowledge, you can progress quite happily and achieve some nice results. I mean, as long as you remember to develop your pieces and make sensible moves in the opening, you can't go to far wrong (at a club level, anyway). Also, it is far easier to get away with only a cursory opening knowledge in blitz chess (there is a reason why some masters use blitz chess as a chance to try out some of their more dubious opening ideas). But when you really start looking at opening theory, you begin to realize that the whole thing was far more complicated than you thought. You begin to see that all the things you were doing were actually wrong and you wonder how you ever managed to live without knowledge of theory. You start to trust the book moves (even if you don't really understand them) far more than the moves you come up with yourself, and so instead of trying to play the best move in each situation, you start playing what the book tells you. This can often result in a drop in your playing level, because you are unconciously focusing all your energies on the opening and neglecting the other aspects of the game.

Now, theory is great, as far as it goes. But at a club level, knowledge of theory can never be a real substitute for your own good chess sense. So my advice is, study theory, but only so you can understand the ideas behind the moves. Just learning the moves themselves can often cause more harm than good, because you will end up getting into perfectly sound and reasonable positions that you don't really understand. I mean, it is better to reach a somewhat unsound position that you fully understand than a extremely sound position that you have no idea what to do with.

They might just be studying the middlegame and endgame?

And getting stronger over the past two months?