Rebounding after bad workouts?

So, I've had an incredible summer of training and have felt really good on most of my rides.  I'm not running right now due to injury and swimming hasn't been a huge amount but it's gone okay. I did an organized mountain bike ride at the end of June and a bike-swim-bike duathlon a couple of weeks ago.  Last Saturday I rode my first half century ride and felt great.  Due to scheduling issues with visiting parents I wasn't able to get out again until Thursday.  I got on the bike and nothing felt right.  Nothing horrible it just didn't feel right.  Then the creepy guy appeared on the trail making remarks to me, who apparently is his sweetie.    I ended up calling the ride short at 14 miles.  I figured it was just one off day.  More scheduling/weather issues meant that I couldn't ride again until Sunday when I met up with my coach for a group ride.  Again, it just felt horrible.  This time my left quad and hamstring were cramping, especially when climbing starting a couple miles in and while I hung in for a total of 25 miles I'd hoped to do quite a bit more.  I'm hoping to do a the 70 mile distance for a ride in early September but at this rate I'm not sure I'll be ready.  So, any thoughts on how to get my groove back or what might be causing the funk? 

I'm doing a swim workout today to hopefully loosen my leg up and get a workout in that doesn't feel so horrible (or if it does it's normal because I'm not a swimmer naturally).