My playoff hopes ride on this week! who do i start?

Here's what truly sucks. You have incredible depth at RB/WR, but especially at RB, your matchups are ghastly! I'm not sure I'd start CJ in Denver on Sunday. I say this because conditions are supposed to be brutal - temps of about 14 and chance of snow. Also, the Broncos do have a very good rushing defense. In a sudden death game like this one for you, it's really important to minimize risk and there's a lot of it here. I guess I'd plug him in there, but this is far from ideal. Stacy is clearly an every week start, but he's up against an ELITE rush defense.

At flex, you may want to consider plugging in a WR instead of an RB. Obviously, you're fine with your WR1 and WR2, but I also think you'd want either Allen or White plugged in there. White has a dream matchup, and he's clearly "back", but this will be tough conditions. Allen's matchup is good, not great, but it's a home game in a must win situation. So I'd say it's a close call, but either one is a very good flex option.

Finally, just trying to cover all bases, but when you say you're not worried about D/ST and K, just make sure that's true. If you've been plugging in the Seahawks or KC all season, it would be a mistake to start either one this week. There are much juicier matchups. And at K, if your guy is kicking in an outdoor game, this time of year make sure to check weather conditions. Sunday could be kind of sloppy in a lot of games, and you don't want that in a must-win situation.