Well I know how you feel but the best start is to start small, pick something to focus your mind on. For example pick writing or have a sketchbook to draw or write your feelings, find a way to express yourself, make note of them. Maybe getting out your feelings will help you and it is good to reflect back on your thoughts.

Also try figuring out things you love to do and focus on how to do something you love, something outside of yourself, sometimes it’s good to get out of your head and focus your attention outward and begin to build a love toward yourself.

I know it seems hard, but don’t worry about school and work, those things will improve when you focus on yourself. Not to get all corny but I’m sure you are a great person but just haven’t found what makes you great and that is what is great about life, it is all there for you discover and that is what makes life interesting. Well anyway I hope you can find things you love and focus on that, you will see your mind start to shift.