Hello Sundance,
I read your post and I've been trying to decide how to answer it. I am concerned on a few levels about your FBS journey.
I certainly am NOT a doctor or involved in the medical field.
What I am, is a person who has lived with FBS for DECADES.
I know there are things you do not want to hear any more, but it would be remiss of me if I did not put in my two cents.
Please take what I say as a person who is concerned for you and who has had personal experiences similar to yours.

As I mentioned above, I have lived with FBS for decades.
First, let me say that Oxycodone is a VERY addictive drug both physically and mentally.
Even after 2 spinal surgeries, my surgeon was VERY cautious about prescribing the drug and frankly I was concerned about taking too much for too long.
Just because your doctor prescribes something does not mean it is the correct.
All you need to do is turn on the TV to see how many people innocently started taking the drug and wound up overdosing or becoming dependent on it.
What happens if you try to not take it?
Have you had to increase your dosage over time as the effectiveness changes?
These are signs to be concerned about.

I am happy to know that your doctors have been waiting at least 90 days for your steroidal shots.
I have been to several pain management doctors and they ALL agree that we shouldn't get more than 3 to 4 shots a YEAR.
However, they do prefer 3.
Too many of these shots can have an impact on the strength of your bones.
I hope your doctor has taken xrays and/or MRIs to determine the exact area(s) that need the injection(s).
I also hope the shots are working.
I did find, for ME, that the shots did not work for more than a day to 1 week.
At that point, my doc and I decided it was not worth the possible adverse impact on my body for such a short return.

So here is what DID work for me...
Sadly, I did not have the luxury of staying in bed when I had a bad flare up.
I had a hubby and 2 children to raise and I was also a full time college student.
My plan had several components that helped....
1. Exercise-when I began to exercise, it was just walking. Everyday, I would walk. At the beginning, my hubby would literally have to drag me. I had so much pain and fatigue, I couldn't get my body to work. Eventually, I was able to not only do it on my own, but I was able to add other kinds of exercise, including strength building, to my workouts.
2. Weight control... I needed to lose weight to take the pressure off my body. For me, at that time, it was joining Weight Watchers. It was VERY slow, but it helped.
3. Aquatic Physical Therapy... Land therapy was too hard on my joints so I found a great place for aquatic therapy. Not only did the warm water feel good on my body, but it made exercising and stretching much easier.
4. Chiropractor... I saw a chiropractor 1 to 2 times a month (at the beginning).
5. Theraputic Massage.... This was a life-saver. I went every other week for quite a while, then every 3rd week. I still do this. I just have to remind the person doing the massage that I have FBS so that they don't inflame me.
6. Meds... This probably showed the quickest improvement. I was given a low dose anti=depressant (not an anti-depressant dosage) to help get me into a deep sleep. Deep sleep is so important. It is the time our body heals. People with FBS do not get into deep sleep. It is not only the reason we have pain, but it is one of the reasons we are always tired. We are missing that restorative sleep. Within a week of taking this medication, I could see the difference in my pain level and energy level.

As I said, this is MY journey that took me over a decade to implement. It took taking the information and suggestions of several doctors, putting it together to see what works for me.
Good luck to you!!