Dealing with leaks in your game

[D.J.]

People have talked about "leaks" in theirs or others poker games whether it be craps, sports betting, table games, etc. Personally I have managed to cut out all those things a while ago when I got serious about poker. My problem is that I take shots at bigger games that I know I can't afford way too often. Just last night I ended a good session of 20-40 with a $1500 win in less than 2 hours. I stayed at the casino a little while longer and decided to jump in a 40-80 game where I proceeded to lose $4K. I did the same thing in Vegas last week when I lost $2500 in a 30-60 game that I shouldn't have been playing in. What's really bad is that in the past 2 weeks I have won over $10K playing 15-30 and 20-40 and blown $6500 playing 30-60 and 40-80. I consistently beat 15 and 20 holdem but can't stay away from the higher stakes even when I know I can't afford to play them. I was so upset with myself last night and I told myself nothing over 20-40, hopefully I'll stick to my own plan. Does anyone else have this problem? If so what is your solution? If not what do you do to keep yourself from playing too high? Any useful comments appreciated.

-D.J.