I fully understand how you feel. Despite wanting to do everything that is "normal" after two lots of spinal cord compression, last week I actually felt quite good, so pushed myself a little too hard. My fitbit stats showed I walked 10 miles more last week than the normal 45-50 miles I usually walk. Unfortunately, I must have changed the way I walk as my back is now aching and pain killers won't touch it.
I refuse to be defined by this cancer, but however unpalatable, compromises have to be made. I no longer go for long walks, breaking them up into managable chunks. Still doing whats necessary, but recognising my limitations. Tiredness is a big problem, as is weakness in the legs. A tip with the fatigue from the radiotherapy is to eat a banana before going to bed. Ridiculous, I know, but it really helps getting you through the next day. Quite hard to face some nights.
I too wonder about physio etc, and will make an effort to see about getting local access to this range of services. Eight years with this horrible disease and have not asked help from anyone apart from the doctors, so maybe time to extend my hand for help.
Best regards