I'm not really sure exactly what my problem is...

I think perhaps the tricky thing for me is the exchange of one advantage for another. Once I get stuck into milking one plan and then suddenly the situation changes, calling for a change in plan, and I still want to stick to my old plan...or something along those lines. Endgame transpositions tend to be a problem as well...

Hopefully these things will sort themselves out slowly, but heck it might be worthwhile to get a couple of lessons. Food for thought anyway.

At what point did you lose your way?  Do you think you let your foot off the gas so to speak?  When playing higher rated players, it's sometimes difficult to maintain the mindset needed to execute the win.  Psychologically, I think it's natural to ease up a little bit in those situations.

Personally, I've always felt that the transition from middlegame to endgame is the most difficult thing to do in all of chess.  I've probably dropped thousands of points in the transition....

I've found that when you are 200+ rating points lower then your opponents, the only way to beat them is with pure chaos (like the main line KID 9.Ne1), or simply play a repertoire where the person who knows the type of position better will win (ie. certin French structures). I am undefeated with the French in tournament games (two wins and three draws) just because I know the MacCutcheon and Exchange French better then anyone else in my area.

Well, I don't feel too bad since this was the first tournament in which I switched entirely to my new white opening repertoire. I'm still really sketchy on a lot of the finer points of the openings and the subsequent middlegame positions. Overall though I was quite pleased with the middlegames I got. I had to play 3 games as white too, so I got extra extra practice!

i wouldnt say you suck, it just what 'experts' are good at!!

it often happened to me as well especially when i was around 1600 strength. I knew more than the experts in the opening, but they had a better grasp of the simplified positions. Even when I was better (even decisively), they stategically held or even won worse games

Yea that sounds about right...all that stuff you just said, I suck at. 

getting past 1800 is all about middlegame to ending transition technique and endgame accuracy . opening is a moot point otherwise!