HELP!

I started having the depo injection around 2 years ago. In that 2 years i would often get my period but it was black & not normal. My new doctor has advised me to stop having the injection. Since i have stopped i have not had my period in around 6 months and i have had massive weight gane and massive mood swings. Do you think it is possible this is caused by the depo shot? I have exactly the same symptoms as everybody else but mine have come as soon as i stopped the injection. Can someone tell me if the depo shot would be the cause of this i need some reassurance because i feel like a fat cow! I have gained 3 dress sizes! Please e-mail me at Glitter_Princesss@Hotmail.com