My Fantasy Football team Sucks!! any suggestions?

My team is currently 1-5. Not to be a poor sport (even tho I don't see how I can make the playoffs now) I haven't given up just so the competition stays honest.

I've been screwed over a couple times from my opponent's defenses of all things. Like week 1, when Delhomme has his worst regular season game of all time ( 35 points for the Eagles D). Last week Titans can't score jack ( Patriots 20pts). And Portis has been mediocre in part because his O-line has been injury plagued.

This is the first time I've ever done FF, and it was a spur of the moment decision (so I didn't prepare much) but honestly I never would have imagined my team could do this badly with such good players.

Here's my team as of today (I've made a couple of drops but only to acquire players that were doing well, compared to what I had).

PEYTON MANNING QB

ADRIAN PETERSON RB

CLINTON PORTIS

RICKY WILLIAMS (recent pick-up)

WILLIS MCGAHEE

MARQUES COLSTON WR

BRANDON MARSHALL

SANTONIO HOLMES

MIKE SIMS-WALKER

ANTHONY GONZALEZ

JASON WITTEN TE

BRENT CELEK

DEFENSES : STEELERS, JETS

RYAN LONGWELL K

figuring Peyton should be good for the rest of the season, I dropped Eli Manning today, trying to get Wes Welker on waivers since 2 of my best WR have byes next Sunday.

SO, any thoughts on how to improve ??? As far as who to package trade ?? I know that I'm stronger in WR than RB depth, but I'd appreciate any trade suggestions, or even just suggestions on who to start next week or in future match-ups. ANY ideas would be greatly appreciated. I've spent hours reading about position rankings, and predictions....I go crazy on Sundays...not sure if I'll ever play fantasy again. THANKS.