Weight gain due Visanne.. HELP

Hi ladies 

I've been on Visanne for 6 months until January 2017, I've gained 8kg and I cannot take it, how long does take for the progesterone to leave your body? I have been experiencing spotting for 4 weeks now, I lost my period ever since I used Visanne so it's starting to come back now. I would like to know is there anything I can do to get rid of the weight I gained? I am training 5 days a week and I do follow a healthy diet. But  nothing seems to happen. Any idea on how to stop the weight gain and how long does it take for your period to go back to normal? TIA