Copper IUD

My boyfriend and I are 95% sure we're done having kids, we don't want to look into permanent options right now because we're both young and could change our minds, but we definitely do not want another baby within the next 5 years. The problem is that I don't respond well to birth control, I already have hormonal issues that I'm being treated for and I'm scared of causing an imbalance. Condoms cause severe irritation for me. We've tried different brands, non latex, but they always hurt. So right now we can't have intercourse, which sucks. What are your experiences with the copper iud? I'm also curious about natural family planning.