This used to happen to me all the time. Just try to remember to stick to the plan regardless of your stack size. One thing that helped me was to keep an opening hands chart on my desktop that I found somewhere online and to have a look at it whenever I was going to open with something very speculative. Then, when I saw how far it was outside of the "green" zone, I managed to fold instead.
Edit: I also keep a 3-bet chart. 2 of each actually, for full ring and 6-max. Obviously they are only an orientation and you need to tighten / loosen depending on the other players. But they help to stop myself from getting carried away...