**Please note, I am only a sufferer not a dr.**
You say: “My symptoms include: neck pain, daily headaches and nausea, constant dizziness/vertigo/loss of balance, ear fullness on occasion, intermittent blurred vision in right eye, right arm weakness, lower back pain, pain when lifting left arm and for the past few days I have had weakness in both legs.”
Loss of balance comes from ears or spine.
If you have seen ENT and got BPPV diagnosis they can do surgery to put crystals in a place where they dont bother you and dont cause the dizziness.
Please, think about this – are your symptoms dizziness as in a spinning feeling? Or faintness as in you feel you may pass out? That might help you in finding the cause.
For years Drs wrote on my record dizziness, when infact what I had was faintness. It was my son who pointed this out. He said it sounds more like faintness Mum. So we started looking at other causes and found I have a heart problem, my heart goes too fast sometimes, SVT.
Neck pain may be pinched nerves, is it a dull ache either side of the base of your neck? I have this it is severe intervertebral foraminal, basically herniated discs causing pinched nerves.
Ear fullness could be a blood flow issue or a blockage in your Eustachian tube.
Blurred vision could be a spinal nerve pinched in neck.
Arm weakness could be a spinal nerve pinched.
Pain lifting your arm sounds to me like shoulder impingement syndrome.
Good luck, I know what it’s like to live with this misery, I’ve suffered 27 years!