Not interested to live. On good things?

Hello doctor, I'm 20 years old. My life has never been one smooth journey so far. There's nothing in my life to look back and cherish. I had discontinued my studies a long ago. I'm home alone for the past four years. Shame, guilt, embarrassment, mental abuse, low self esteem, Negative body image, mental abuse, physical abuse, long term mental illness, etc are the words mostly associated with my life. My mother had died why I was 2 years old. My father has remarried and abandoned me since then. I was brought up by my grandfather who is 82 years old now. Despite his age, he is taking care of me very well. I'm dying every second. My mind is killing me in thousand ways it could. I feel shame and embarrassed everywhere I go. Some people are pointing toward me and laughing(this is not my imagination, it is real). I know people who like to laugh. I'm someone who always likes to cry. Is it possible to forget/erase all my past and to start a new life by focusing on good things? Help me.Thankyou