My cat ped away 1 week ago; has only visited me once, i am so depressed he left me? please help need advice?

he jumped on my bed 1 day after he ped away but he doesnt appear to me anymore. i am so depressed i feel i should end my life and have nothing to live for anymore. i also feel maybe my cat has moved on and forgot about me or doesnt love me. i have asked God to make my cat another vessel here on earth and have my friend call me and say she found a newborn kitten and that I would instantly know it was rex reborn. I am losing my mind. i balme my boyfrined for his death because he fed him scraps of sandwich meat which i thought caused him to lose his appetite and make him not eat his own food and make him susceptible to dying since he was already sick and needed to eat. he was 17 and had hyperthyroidism and as far as i know had kidney disease. i gave him medicine and subq fluids everyday. but i feel i didnt do enough. he was scheduled to get his I131 radioactive cure for his HT on 1/12 but died on me 2 weeks before his treatment. I am in so much gried. i just want to die. life is meaningless wihtout him an dfamily doesnt care enough about me to ask me whats wrong or be there for me. my mother told me to go home that i bother her, and my sister says she doesnt have time to talk with me. i feel so alone and scared.