Have you tried talking to your teacher, it can be really hard to ask for help, but when someone reaches out to you then you should try and confide just a little.

The emotions that you are describing are all very typical of depression and only too familiar me and to many others reading this thread. We are all very good at saying to someone else "you are not a bad person, it is the depression that makes you feel that way" but we can be weak when it comes to believing it for ourselves. You're not alone and no-one here thinks you're any of those bad things you said about yourself. We want you around and want to see you keep posting.

Yes depression is a horrible disease, but it can be managed well with the right treatment. Hang on in there.