Regarding neurological issue. Perfectly?

Hi sir, when i sleep at night at some point of time in 5 am i got some abnormal sensation like muscle twitches in whole back mainly upper thoracic region,head cramps, and a freezing feeling in toes( fingers of foot),lower abdominal discomfort ,littile muscle throabbing(fear) pain in chest and hip muscle weakness and a sensation of urgency to wash room(but no poop ).i am using gabepentin and tapentadol tablets.the doctor diagnosed me with b12 deficiency after seeing eeg and ncv test.and i took 5 b12 shots(which abnormally increase b12 level)>2000.i did mri for whole spine which is normal(no nerves compressed) .ct scan for chest qhich is normal.all tests for abdomen which are normal.i did bence jones protien test which is absent.and hlba 27 - is absent.so may i know the exact diagnosis and cause and how long it will take to recover if i take medication perfectly?