You did not set out on this trip to physically abuse yourself; you wanted to see the country from the vulnerable position of your bike seat with the bare essentials to stand toe to toe with whatever bisects the road you're on. This is not a race but, you've found yourself racing the changing of the seasons which is why you are not 100%. Physical pain prevents you from enjoying the road, the main objective of this trip. If you do not ride your bike into Portland you will not have lost anything. If you started this trip earlier you would've had plenty of time to take regular days off but, that was not the case and you can't do a damn thing about it now.
You have rode over 3,000 miles on a bike that was built before the year 2000, it's been an unforgettable ride and I'm sure from this point on you will not forget to listen to your body, to be fully aware of any physical limitations. How important it is for all of us to take care of our own needs at our own time for time itself is a goddamn illusion that makes us rush and hurry and worry. Well, I can't justify hurting myself for the sake of achieving some sort of goal. I just want to ride my bike, dammit.