Change my Style?

I've been playing poker for a while, I'm a little young and cannot afford to play higher stakes so I usuually stick to lower stakes online. Early on in my poker career, I was winnign and winning a lot, but lately I feel like there's somethign wrong. In S%G's I play tight during the early part and loosen up accoridngly as the game progresses, I select my hands according to my position and my stack level and I play them agressively trying to force people top make decisions. For reasons I don't know, I never hit my hands, 1 out of 10 I hit something decent on the flop, so if I was leading I bluff to steal the pot. Again in the past, this has worked, but lately it seems everyone calls me down when I bluff, or I never get a decent hand and when I do I don't get paid off. This may just seem like a rant, but in 5 dollar SnG's or .25/50 I need advice on where my game needs tweaking. I usually make decent reads, and I don't make dumb out of position moves. If it helps, my game is heavily influenced by Doyle Brunson's Super System, just I play a little tighter and conservative than what he suggests.

Do you know your stats? If not you're opponents likely do (at least the ones calling you down). Maybe you making too many "moves".

I play on Bodog though, opponets can't track each other's stats.