Not Cathe, but a certified trainer...
Also, nothing even close to Cathe here, but I am a Certified Personal Trainer, and I have several clients who have come to me in your same situation with the low back pain...
I would really like to recommend you take some time to incorporate some yoga stretches as well as neck stretches throughout your day, as your neck can carry over to cause low back pain. If you are hunched forward or have your head down alot of the day, your lower back will be overcompensating to let you hang forward....Try these few stretches throughout your day....
1. Head circles...put down your pen or stop typing and do 8 head circles clockwise and 8 counterclockwise SLOWLY and stop when you feel a tight spot and hold while you take 3 deep breaths slowly....
2. Shoulder shrugs...sitting on the edge of your chair, inhale and bring your shoulders to your ears and then exhale and relax them all the way down your back. repeat 3-4 times
3. Forward bend....while seated push your chair back from your desk, and open your knees and roll your body down slowly to hang between your knees....stay there and breath 3 deep breaths, all the while think about relaxing your low back.
4. Seated Twist.....sit on the edge of your chair and place your left hand on the outside of your right knee and your right hand on the chair behind your and twist, pulling your belly button into your spine. Hold for 3 breaths and then switch sides and repeat.
5. Standing low back stretch.... Stand at your desk and lift your right knee up and hug it towards your chest, and hold for 3 breaths (do this against your desk if you don't have much balance) then repeat on the other side.
6. Spinal rolls....Stand with your feet hip width apart, and start by tucking your chin into your chest and one vertebrae at a time, roll down slowly, bending your knees until you are hanging all the way down with bent knees to protect your back, then slowly as you breathe, stack your spine back up one vertebrae at a time with your head coming up last. Do that 3 times...you're back will just feel like you've had a massage!
When you do your exercises, focus on strengthening the upper back to hold you up properly so that your low back doesn't overcompensate for poor posture. Back rows, and reverse flyes and lying hyperextensions can do wonders for improving your posture so that you allow your low back to not have to work so hard. And after exercise, really stretch your hip flexors and hamstrings well, as they get very tight from sitting...Also, do NOT neglect core work!!!
One other thing you might try is make sure your chair fits you ergonomically. When seated, check that your back fits comfortably against the backrest and your legs should be at a 90 degree angle with feet flat on the floor...if they are not, put a phone book or other block under your feet so that you can make them flat.
There, I hope that offers you all some sort of relief! It has helped my clients! Have a healthy day!