Prolonged/Heavy Bleeding on Mini Pill

Hello, ladies! I need some outside opinions on what might be going on. So I started the camila progesterone-only pill in November 2017. I’m 19 and this is the first ever birth control method I had taken. Ever since then, I’ve had only 1 “normal” menstrual cycle month (which happened in June). All the other months though, I have been bleeding for 1.5 weeks to 2 weeks straight heavy bleeding. It stops for about a week and then starts back up again. This month, I had bled out for 2 weeks, it had stopped on the 11th, and now it started back up again. I was wondering if any of you have experienced this before on this birth control. My doctor says to keep going on the pill but the bleeding has become such a burden on my life that I can’t do normal everyday tasks because it comes with cramping and clotting. And I don’t think I’m pregnant because 1) this happens literally all the time since November and 2) when we have sex, we also use condoms 100% of the time and he pulls out before he ejaculates, plus I’m also on the pill so we’re super safe. I take my pill everyday at the same exact time (6:30pm) and I have never missed one. I just want answers ://

Some more information: I got an ultrasound done and it looked normal. I also go blood work done and it came back that I had low white blood cells and platelets, with signs of anemia because of the blood loss. I also cannot take estrogen because of family history, and I tried an IUD but I have a very small cervix and it won’t fit. Progesterone is the only thing I can take, but I’m not even sure if my body can anymore.

Please please please let me know if any of you have experienced this before. Thank you! ❤️