I started my employment a year ago as an Administrative Assistant

Within 3 months I was promoted to Payroll Administrator/ HR Assistant (no experience but I excelled).

Within 7 months of my hire date I was promoted to HR Coordinator and replaced the HR Management position after my HR manager made a disaster and quit (at this point I had 4 months of HR experience but I was extremely excelling). They did bring in their former HR manger who had been with the company for 10 years as my consultant and consultant for the Safety Coordinator. 

Now after 9 months ( i know I have excelled, one of his few best workers busting ass 11 (and sometimes only claiming 9 hour days.... putting 150% in) since being HR Coordinator,), my boss informed me they would be firing my assistant and Safety Coordinator (they are extremely horrible at their job) and that my HR Consultant would becoming back full time. She would need an office, so I would have to give up my office and go back to my assistant desk. 

My boss also stated that I am doing a wonderful job, nothing wrong with my performance and I would continue to do the work I am doing plus the work my assistant was doing ( So being someone's bitch again).

I am so confused and at a loss for words especially since my Consultant had a excellent job, she was working with her mother and was going to become director in about 3 years and also made her Best Friend go work for her about a year ago. It surprises me why she would leave so now (leave the wonderful medical field to come work for a barely making it rice mill field)

I am really questioning everything especially since he says I am doing a wonderful job. At this point, I am Wondering if I am even of value or they want me to become admin assistant forever. If that is the case I will be looking for a new job because I know my worth and what I bring to the table.

Any suggestions or thought would be nice?