Sounds like your back is taking all the load for your activities. I have a few recommendations:
#1 Id recommend strengthening your glutes and abdominals as this seems to be a major cause of back pain in general. Exercises I recommend for this are glute bridges, fire hydrants(where you look like a dog peeing), cat camel(active flexiblity for the back), pillar bridges, side bridges, and/or pushups. Doing at least 1 set of these per day of the bridges work great as well as pushups. THe other exercises I suggested can be done for 2-3 sets of 10 reps.
#2 Do leg exercises like lunges, overhead squats with a pvc bar or broom stick on a daily basis and it will help build your leg strength and core up besides doing needless crunches. 2 sets of 8-10 reps with great form help your flexiblity and strength out in general.
#3 Learn how to use a foam roller(self massage) or tennis ball and find trigger points in your legs, upper back, etc... Most of the time you get spasms in other muscle groups that cause referred pain in other places(i.e. tight piriformis causes sciatica and/or back pain even though its located in the glute). Release these spasms or adhesions and stretch them gently after your sessions and you will start to bulletproof your body from injury. If your unsure of how to do it, going to a massage therapist a few times to help identify your troublespots usually does the trick.
#4 Take a high dose of fish oil. Fish oil reduces infllammation naturally without painkillers and aids in healing. I recommend a dose of 3-4 grams of epa and dha(look on the back of the bottle) and it will build up in your system for any pain that your experiencing.
#5 Learn to stretch daily with movements and use of static stretching before bed or after workout. Movements can be lunges, arm circles, hip circles, ankle circles, etc.... Any dynamic stretch seems to help. It will strengthen the muscles and joints as well as get you out of pain over time.
Above all else, hang from a chinup bar to decompress your spine at the end of the day. Inversion tables are a good substitute, but I recommend less time hanging fully inverted and doing them in for 10 secs then coming back up and repeat 5-6 times.
Just keep moving and don't stop. Back pain does hurt(and I know from experience), but keeping active will stop it and prevent it from further damage.
Good luck,
Aaron
