What kind fusion did you have? How many levels? What area: lurabar, thorasic or cervical?
More info would help to answer your questions.
In general it all depenRAB. More levels are done - longer healing process. Also depenRAB on surgery. Some fusions are more complicated than others...
Usually a year or so is healing time after major surgery like this. If nerve pain involved, it may take a year or 2 to heal...
Take care!