When you off these medications, you begin to feel your own feelings again...and that can be very good...sounds like you are reexperiencing the suppressed feeling that happens after a hysterectomy...some real life, but tempoary, depression about the loss of what might have been, but can't be. Process it, don't panic, just feel and think and sort things out.
Feeling depressed and tired can be normal. I would have concerns because you mention 'two serious bouts'. This is something you need to monitor.
I sometimes have a desire to have a baby/ babies. I am not in a relationship but sometimes I feel I could be a total **** just to achieve this (although this goes against all my values and beliefs).
I think it can be both biological and psychological.
I don't know if this helps much.