Birth control

So I’m having a major issue with birth control. I had an IUD for a while and absolutely loved it I barely had my period the whole time and it was great. The downside is I gained 25 lbs and no matter how hard I tried the only thing that helped me lose weight was getting it taken out. Now I’m on pills and they’re fine I have no issue, but I started gaining weight again so this month I tested it out and went off of them to see if I would lose weight and lo and behold I have been losing weight every day this month so far and I’m not even dieting or exercising. I just really want a birth control that will not cause weight gain or I’m wondering if I would be okay just using condoms?