TeenHelp - i feel lonely

I feel so alone and desperate. it seems no one wants to talk to me. I message people and they reply but then they make some excuse and stop talking to me. I feel like an idiot who is always wanting to have someone to talk to when nobody wants to speak to me. I feel so alone and insignificant and no one cares. even if I initiate the conversation myself the other person never seem interested. I have no idea what have I done. and apart from that I face so many failures in my academics. I am living my life like a worthless creature and it really hurts that I cant have even the most basic things in my life. I try to remain positive but I have no clue for how long I can keep myself from going totally nuts. I mean what would befall anyone if they start a conversation with me. but still nobody does .