I feel so lost in life ....?

Please, just give me some advice or solution on how to get out of this hole I'm in. I'm 18 and have social anxiety. - i have no friends - am distant with my father and don't get along with my mum - I smile to ' fool ' people I'm happy but I'm really a little fed up and tired of life. I haven't felt happiness in over three years and I'm deeply depressed. I cannot talk to people and avoid at all costs any situation social. I would rather shoot myself than endure a situation like that. On my 18th birthday I stayed alone in my room and played video games, and I didn't receive a single text. I have a job, pay my taxes and pay my way through life. I feel like crying out of frustration but feel helpless because I feel no emotions whatsoever ever. I am socially invisible and am not important. Imagine how it would feel to know that you will never achieve your dreams, be alone forever , and never be happy. Ok? Believe me here ,, I do not dramatise my problems. But I'm pretty sure 99% of people with this problem how I am now would of broken down or killed themselves. It's all up to me but after countless attempts i feel so helpless. Please don't say see a doctor. I'm seen many and it never helped. Neither did medication. Is this my destiny ? :(