You suggestions. Life? plz suggest me?

Hii doctor, I am 24 years old working girl. I m doing night shifts and in a day time I m also doing some classes. From earlier I m not feeling well every time I feel sad with full of negativity and disappointment I feel like nothing is going good with me with my carrier with my life what will I do? Will I get the success in my life? Every time I feel no one with me no one even love me. I don't want to smile even but I have to laugh (no option)! Because I don't want sympathy from anyone. Sometimes I told cough syrup and crocin medicine wid no reason I don't know why I had. Yesterday only in my office my manager gave me new work to do but I was not able to start so he and my team leader shouted at me very badly that time I felt very disappointment and I felt I cant do anything my life is waste it was very easy how can it happen I cant do this. I felt I have to leave this job right now so I talked with my manager to allow me to go home but he didn't allow and I cried. plz suggest me ?