Recently told my B12 is low.

Not sure if i'm in the right place here, thought i would write a little. I'm 44 and for a few months have been feeling tired, tingly feet and lower legs, always seem hungry but eat well including lots of meat, dairy products and veg. At work some simple jobs have turned out to be very difficult and I become confused and stressed out, takes a while but fortunately I eventually work it out. Have had frequent bouts of diahrea. Occasionally pins & needles in hands on waking, even though not been laid that side. Floaters in both eyes, seem to be getting worse, forgetfulness seems to be coming on.
Anyway, about a month ago saw my GP and had bloods done. He said my B12 was low (169) and put me on cyonocobalomin 50microgram tabs, one per day for 30 days, had another test, phoned surgery and receptionist said all normal and to finish my tabs and thats it. I asked for reading of B12 and she said nothing to worry about, all ok, but could not tell me the reading as GP had not put it down.
Still feel crap all the time with my symptoms. Does it take a while to get better. ??? Think I will phone and see my GP again, have read loads of stuff about B12 deficiency and just prob scared myself. !
Mark