In the words of Nike "Just Do It", then my husband said on recent 74 miler (longest ride to date) "what doesn't kill you makes you stronger" (guess I'm stronger). And then I tell myself "if it is to be, its up to me". I also agree very much with John Lennon.

I don't mean to make light of your concerns. I've been dealing with that a lot myself. I'm just finally able to say "I'm riding the two-day Seattle to Portland (200 miles) ride in mid July. Until the 74 miler a couple weeks ago, I was saying I was "signed up" for the STP. Now I actually feel like there is a possibility I could actually do something that incredible! Yes, it will be painful, incredible hard and exhausting. It will be the toughest thing I've ever done both mentally and physically. I know what you mean, finishing is a great accomplishment. But I guess if we don't then we can say "this time it wasn't meant to be"

You have gotten lots of great advice from the ladies who know a WHOLE lot more about biking, so listen to them. Just don't discount yourself too soon! I think you can do this.

Oh and one last quote "I haven't met a hill I can't walk up yet". Unfortunately I have to use that one every now and again. So if you have to walk a while, that's ok too.

Good luck and continue to enjoy the training time. You have the right attitude. Ride for the fun of it. Oh, and yes. Take the Map My Ride route if it has less climbing