Double Chain Ring...yikes

[alpinerabbit]

Now is the casette the one on the back? I would have thought that the crank would be a lot cheaper to just add 1 chainring that taking the casette appart and adding just one chainring.

What Andrea said, and of course you can't add a chainring to a double crank. You can exchange, but the minimum small chain ring in the front can be 38 teeth.

How much will this cost...
A cassette sets you back maybe 60$.
A Compact crank will be around 150$?
I assume you have Shimano 105 for that pricing.

Do change to a compact - you are obviously overtaxed by the regular. You can almost do your tour but it's too much for you. You'll do much better on the compact, talk to your LBS what they can do for you (do they need to replace the front derailleur?) and pricing instead of torturing yourself.

Wrong gearing has little to do with the price of the bike... do treat yourself, stop being frustrated and then enjoy your ride.