I have a metric century coming up in 3 weeks. I've done 800+ miles this year, but much of it was shorter distances as I got ready for a sprint triathlon in April. Since then I've been ramping up my riding, trying to get ready for this event. 2 weeks ago I rode 30 miles and it felt great and easy. Last week I rode 40 miles in some strong winds and I felt grateful to even finish. Yesterday's 42 mile ride was similar. I can't imagine riding an additional 20 miles under similar conditions. I'm starting to have real concerns about being able to finish this ride. I've got 2 more weekends to train for this. I am planning to keep next weekend's ride around 30-40 miles because I have a 4 mile running race on the 26th, but then do about 50 miles on the last day of May.

Any training suggestions or ways to gain more confidence for my metric century ride?