Prior to this tour, how much riding did you do? Did you ride at least the distance you would be riding on this tour? Did you experiment with saddles and bicycle fit to make sure you'd be comfortable out there?

If you were not on tour ... if you were doing practice rides in preparation for the tour ... I'd suggest things like trying other saddles, raising or lowering your saddle, moving your saddle forward or back. But since you're on a tour, it's a bit more difficult to try other saddles. I suppose you could experiment with adjustment, but be careful and only make very slight adjustments. An incorrect adjustment could lead to serious knee and achilles tendon issues.

Are you currently wearing padded shorts? If not, you might want to stop in somewhere and buy a pair.

Another idea might be buying a gel saddle cover ... but note that those gel saddle covers have a thickness to them, and you may need to lower your saddle by that thickness so you don't end up with knee and achilles tendon problems.