Peg, I assume you're in USA.
I was over there recently whist suffering severe lower back pain. I checked out Chiropractices and found them seriously expensive. It's MUCH cheaper here in U.K.
I would endorse the Hot & Cold treatment, also try a search including athletics in your criteria. Lots of athletes suffer all manner of problems, and as they tend to be quite motivated people you should find some practical answers to your problem.
If you are in spasm, a decent massage will undoubtedly help, but ensure it's carried out by someone who knows what they're doing. Simply rubbing the area is not the answer.
Re: backpacking. If you are literally backpacking with a large pack, and intend walking distance: try walking poles, also ensure that the straps of the pack are arranged in a way that will keep the weight on your hips, and also ensure the pack is balanced and not pulling you forwards / backwards / sideways.
PM me if you need details of chiropracters (s?) / physios here in the UK.
Enjoy your trip anyway!
John (in Manchester, NW England)