sort out my life

I’m 17 and have nothing to live for, no one understands me, no one knows me. I left school last year and dropped out of college because of lonliness and depression. Ive had no freinds for about 4 years now, (and im not over exagerating) my family just think im being sill but the worst thing is when you think you have got your family supporting you, my own brother, cousin and aunty cut me out there lives because they were ashamed of me, my grandad basicly said he did care about me and i dont even recall a conversation with my uncle ever. Over the past couple of years i have put quite alot of weight and i must admit i dont stand out in the crowd and never have. i have always been someones freind or relative. i wasnt even noticed sometimes. I was bullied and that was the only way people noticed me. no one has ever known me for me which there is nothing to know.
Im jobless and i have no money. i am constantly being critisized for not doing anything with myself, no one understand what i actualy go through. I have got no confidence and low self esteem.
I dont exactly dress nice or ever look nice. I feel my past is going to ruin my future. I am a waste of space seeking guidence on help to SORT MY LIFE OUT. i feel that if this doesnt happen soon i am going to crack.