Struggling to be consistent

[SteelPoker]

I have been playing NL for about 3 1/2 years. I am fortunate enough to be on the positive side (although only about $2,000). I can't seem to sustain any momentum. I will run good for a little while, then what seems like the impossible beats start coming. Am I alone? I feel like I am pretty decent since I am ahead, however I would love to make a good second income at poker. I go through spurts like I have been the past week where I will continually get my money in with the best hand and lose. I generally play S N G's (6 handed), $13 - $25 buy ins and have today alone been knocked out in third 5 times. Three of the five I had AK and flopped a K only to lose to someone flopping a set. The other two I was in after the turn with the best hand against a draw and lost. This is a recurring pattern that I can't seem to shake. I am at my wits end. Anyone else have this problem? Anyone who has any advice it would be greatly appreciated.