You list your age at 14 and I think you are very tuned into your feelings. The conditions in your home sound like they are a large part of what is making you depressed. If it were only about you, you would feel this way no matter where you went. The circumstances you are in are contributing to your feelings. When you are at home the home environment makes you feel depressed. When you are out of the home — you feel better. Take this as an important piece of information and keep developing more and varied interests outside of the home. Find people, places and experiences that fill you up — not drain you.
From what you tell us of your mother, father, and brother they are not connected to your feelings for different reasons. Your father by thinking it is only boredom, your mother by not wanting to hear your negativity, and your brother because of his condition. I would try again to talk to your parents, perhaps by saying what you enjoy about the time with your father and how much you would like to have more meaningful connection with your mom. This may help them realized they need to spend more time doing the things that help connect with you.
Wishing you patience and peace,
Proof Positive Blog @ PsychCentral