I win at small stakes, but then I blow it all....

[McFatSauce]

What's up guys. I'm new here. Just asking for advice.

I tend to do very well at smaller stakes sng. From single table to 45 man, I generally make money in every tournament I enter. Then I think to myself "Man, I could be earning faster money" And blow it all + more on cash tables (limit and NL) and higher stakes SNGs and tournies. Should I just stick to the lower sngs? Am I only succeeding because only fish play at lower stakes? Thanks for the help.