Birth control pros and cons

Okay so I talked to my doctor today about my periods because they have been pretty bad lately like double over in pain cramps and super heavy, I wear a tampon and a pad to bed and still bleed through sometimes.... so anyway she suggested birth control, well she was talking to me about the pill and that didn’t work before because I wasn’t able to keep up on it. She said the Nuba ring was pretty good but I’m not sure how comfortable I feel about trying to put that in me by myself, so then she said something about the IUD. I’ve always said absolutely not to the IUD because I heard it can cause infertility issues, so if we decide to ever have anymore kids I am afraid of getting the IUD. She also suggested the depo bir I heard that can cause a lot of weight gain and I don’t need that as I am already trying to lose weight... so my question is, what are the pros and cons of an IUD. Does it affect fertility? Which birth control would you get..