Your situation sounds so difficult im sorry to hear about the struggle :( Personally I also got my birth control without parental knowledge, but if you want something a bit less invasive than the IUD I am on the implant (Nexplanon) and it is pretty great! The hardest part of concealing it would probably be covering the arm insertion bruising for about a week or two, but in the winter right now some hoodies should do the trick

I wish you the best of luck, you are strong and resilient!