Firstly, don't think you're not good enough person to start reading Gurbani. Anybody can read Gurbani, and if you feel to then go ahead and read or listen to it. You can start off slowly and gradually, and it's up to Guruji of how you will be graced.
Have you seen your doctor about the depression or low mood you maybe going through? It seems like others are off loading their problems and dukh onto you. But you're not a counsellor either.
As MisterrSingh paji has asked if you have any interests or hobbies, divert your mind from the same old negative environment with these. Maybe attend classes at a community centre or even if there's anything happening at the Gurdwara, and you wish to go, just go for the change of sangat, e.g.: if there's a Kirtan programme or any katha.
You could also join education classes with people like yourself, or alternative therapy courses, exercise classes, anything that you maybe interested in, flower arranging, etc. This will be better than be glued to the internet, as you will get to communicate with people in real, that will have a positive effect on the negativity and make you stronger to deal with what's going on.
Your father's sisters and cousins probably talked down on you as they think they are doing the elder role by being advising you, but some of our people just don't have those skills, so don't let them get to you, they just don't know how to support somebody.
Have you ever talked to your father about how you feel? It would be an idea to do that, then he will at least know what you are going through and it may make him realise that he's not the only one that needs the support. Your grandma is your father's mother? Explain to her how you're feeling, and she may have a word with him. Does your step mother make any effort to talk to you? What does she do ?
Also get some counselling, as this willl help you with what you are going through.