My Mum is still controlling at 27, although I moved out at 18 to go to university. She suffers from anxiety and depression and really it (in your case too) is her insecurities talking. I've never admitted to birth control etc. and don't think you necessarily need to discuss it with your Mum. Mine is Christian and there are some issues there, although I have lived with my boyfriend for 7-8 years (not easy with my depression/anxiety!)
I am going over a lot of it in therapy. It is awkward as you can't choose your Mum and obviously I love mine and have to keep seeing her, but it can be so difficult to get on.