IUD Paragard or IUD Mirena vs Implant Implanon?

Ok I need to get birth control. I can't take the pill because I would forget to take it. I can't take/have anything with estrogen in it because I am breastfeeding and my dr said it affects milk production. I've been looking at the IUD Paragard or the IUD Mirena vs the implant Implanon. I've researched all of the options, but I've heard horror stories about all of the options I'm currently considering. Any help would be highly appreciated.