You are such a good person and have loved and supported the people that should have done that for you throughout your childhood and as a young adult. Losing your mum must have left a massive gap in your life and you will feel completely destabilised, but try and start to think about you and what you want from life. You are still so young and can completely turn things around. Please don’t let your dad grow into the space your mum has left behind. Think about going to your gp, tell them what you have been through and ask for some counselling. I hope you have other friends and family that can help you to find a way forward. Keep posting on this site, it’s very friendly and supportive.
You sound lovely and you deserve to be happy x