is it my IUD?

I got my IUD put in at my 6 week check up after I had my son. So I've had it about a year. I gained 60 lbs while I was pregnant topping off at a whopping 175 and I have been able to loose some weight (I weigh 153, but I am no where near my prepreggo 120. I am dieting, exercising, and doing everything I can to loose weight. I am only 21 and it shouldn't be hard to loose this weight. I also get really angry all the time. I don't feel like that is something that I generally do. I am tired all the time and have no desire to have sex with my husband. This might be a mixture between hormones, and being 30 lbs overweight and wanting to cry every time I see myself naked.I have times that I feel really positive and that I can do this and I can change and I can be better and get thin. But then it gets really bad for a while and I can't see the end of the tunnel. I don't think its postpartum depression, I love my son and my husband and this has just been going on too long. My periods have been pretty regular if a little long and I have had normal cramping. However I can really feel every time I ovulate and that is really uncomfortable.

I am having a hard time trying to tell the difference between things that change after you have a baby and side effects from the BC. Has anyone had any similar side effects? My husband and I are not thinking about adding to our family and I got pregnant while on depo, and I never missed or was late on a shot, so this is one of the only options (other than good old condoms.)