Hello and welcome to the forum,
I think you are very wise and have identified your problem which is causing your anxiety. Back pain could certainly cause your anxiety to spike.
Regarding Tramadol -
Orally disintegrating tramadol is approved to treat pain in adults. Specifically, it is used to relieve pain that is moderate to moderately severe in nature. Despite what was originally thought, the active ingredient in this medication has significant potential for abuse and addiction. Tramadol is classified as a "centrally acting opioid analgesic." This means that it works in the central nervous system (the brain and spinal cord), acts much like morphine in the body, and relieves pain. Do to its analgesic effect it may appear to be making your anxiety better.
IMHO, I would use this medication for the reason it was prescribed as it may become very addicting for some people. There are currently no universally accepted off-label uses for orally disintegrating tramadol.
I have been on it for pain a long time ago but did not like the feeling .
I wish you peace and hope your back pain gets better.
Kindly,
Kitt