Lower back pain from Lymphedema

I have had lower back pain from all over lymphedema for years now.  Most likely the cause is that as I have my limbs compressed during the day, have my limbs drained daily with my flexitouch machine; but do not have anything that compresses or drains my lower back.  I am currently at the lowest weight I have been at, since being diagnosed with lymphedema 8 years ago; however, my lower back pain is the worse it has ever been.  It feels that now that I do not have so much weight and fluid sitting on my lower back, the fluid that I now have pushes directly on the nerves in my lower back.  This pain interferes with my everyday activities and my ability to sleep through the night.  I currently have been on 40mg ER Oxycontin twice a day for about 6 or 7 years and take 50mg Nucynta for break thru pain.  Even with these doses of medicine, my back pain is debilitating.  I have also added ibuprofen, instead of the Nucynta, which helps but does not take the pain away enough so that I can keep up with my daily activities the way I would like.  I have several options at this point, increase the dose of my medicine, which is my least favorite option; get new pieces for my flexitouch machine if I can afford it, gain some weight back, or continue to deal with the pain.  I have an appointment tomorrow with my lymphedema therapist and a flexitouch representative to look at my current flexitouch setup and take measurements.  We think due to the change in my measurements, since I purchased the machine 5 years ago and the fact that the new pieces cover my lower back area, that my insurance should cover a replacement.  I hoping with that option, if approved, that my 20% copayment will be affordable.  I am trying not to put all my hopes on this option, but in truth, I am and hope that it works out so I can purchase it and that it takes care of my pain.  I do not want to gain any weight back, that has been so hard to come off and like that I am in a size 12 now and feel so much better.  I can also not continue to deal with the pain, as I have only slept thru the night twice in 3 months and there is so much that I am not able to do now, that I want to do.  Dealing with a chronic illness, means many different challenges come up and must be worked around, dealt with, or knocked down and I am determined to knock this one down.  Stay tuned as I update after I go see my therapist and flexitouch rep and go thru the insurance maze.  Wish me luck!
Update after LE therapist appointment and meeting with Flexitouch rep:   I had a very productive appointment yesterday at Retreat with my LE Therapist and our Flexitouch rep and wanted to share a couple of things we discussed.  Our main focus was on my increased trunk swelling and severe back pain that has impacted my daily mobility and pain levels.  I brought in existing pieces that I currently use with the Flexitouch machine I have had from 5 years.  I was hoping that I could keep the machine and just replace the pieces; however, with the changes they have made to the machine and pieces I will have to purchase a new machine.  The rep and therapist seem to think I have a strong case to submit to the Anthem fep insurance for approval, since I have had the machine for 5 years, the new pieces will address my trunk swelling, specifically under arm(my measurement has increased 5cm since last July, which is significant), lower back swelling, and genital swelling; the increased swelling is affecting my sleep(I have only slept thru the night twice since the beginning of the year).  The only concern we have is that the new pieces will not meet enough to address the lower back swelling and we plan to meet again to trouble shoot once the pieces come in.  In the meantime we rigged my existing pieces o that they will fit snugger on my lower back and decided I would drop back my machine time to 2 cycles per day, instead of the 3-4 cyles(hours) I have been doing.  They now have studies, that show it is not necessary to do all cycles per day, when you have all over LE.  The studies were not available when I first received the machine, so I am happy to gain back 1-2 hours of my day, not being attached to Flexitouch.  It will take 2-3 weeks before I hear if the insurance approves the new purchase, in the meantime they will work up a price and I need to find a way to afford this, because right now with my daily life impacted I don't feel I have another valid option.  I will update again when I hear something and praying it will be good news that the insurance has approved the purchase.