I leave on my trip the 26th. Fort Worth, Texas to Carlsbad Caverns, NM...to Yuma, AZ hopping across to California to see the desert sand dunes and I haven't ruled out crossing into Mexico...Grand Canyon, AZ possibly overnighting in Flagstaff...Durango, CO...Dodge City, KS...Amarillo, TX...then back home. 3,000 miles in probably seven days. Once I get to Yuma I can cut anything else out of the trip, but so far, that's the plan.
New seat, and try changing postions a bit when riding also best to try and relax somewhat. If your tense everything will get sore that much faster. Stop every hour and walk a bit. We ride 300 plus two-up quite often and found you need to do these things for a good ride.
Check out Corbin. They make seats with ergonomic design and a backrest. I've got one without the backrest on order, will have it on the bike for a weekend rideout in a couple of weeks. I'll post how I get on with it.