Heavy legs....

I experience something like what you described - with the sense of heavy legs and the pain and loss of sensation etc... I have been diagnosed with many spinal problems mostly in the lower spine but recently I was told I had cervical myelopathy - a serious condition of the neck.

If you "google" cervical myelopathy or myelopathy - it will list the symptoms. The sensation that your legs are very heavy is a main symptom. Also, spasticity in the legs - the feeling like you cannot stand up - that your legs are going to give out or they do give out - and the loss of sensation...could be a cervical neck issue.

Your symptoms could be neurological in nature - I would recommend seeing a neurologist or a neurosurgeon to see if they can figure it out.

Good luck and let us know how you are progressing. We all care about you.