Stay strong, these are tough years for many, I know this as my daughter suffers as you are. These years will pass as you move into the next phase of your life, take one day at a time, allow yourself to forgive you.
Try to connect with your family as deep down they are on your side, and will be there for you even if their understanding isn't always great.
Also please do one thing for yourself, any sentence or thought that begins with "I can't" needs to end with "yet"! When I was young I couldn't drive, did that mean I could never drive? No it just meant that I couldn't drive yet, because I wasn't old enough yet and because I hadn't learnt yet, I can drive now though. So forgive yourself for what you haven't achieved yet as there is a lot more to come still, with a lot of "yets" to be accomplished. You are in my thoughts and I am hoping for better days ahead for you.