Since when are you experiencing these symptoms? Are you diabetic or hypertensive? Are you on any medications? Were any investigations done? Any significant health history?
If your MRI of the spine has not showed anything; you need to get an MRI of the brain as the next step. Neurophysiological studies like electromyography (EMG) would also be advised. Consulting a neurologist would be prudent. Your symptoms are quite significant and warrant investigations as soon as possible. Balance problem denote towards cerebellar dysfunctions while rest of the symptoms need to rule out the white matter changes in the brain.
Getting serum levels of vitamin B12 is part of the work up to rule out any peripheral neuropathy.
Please feel free for your follow up questions.