Hi, My Sister's Husband Has Mental Illness Bipolar, And Hallucination.

hi, my sister's husband has mental illness bipolar, and hallucination. his treatment is going on for almost 8 yrs. he eats tobacco from his early age he is 40 yrs old now. he is trying to quit tobacco for 14 days. He was eating almost 40 nicotine chew gum daily. for three days he stopped to eat chew gum as well. He lives in India and i live in USA. since yesterday he is calling me and told me that he loves me. I dont know what to do. few years back, for three times,
he went in bad situation and two time he was violent. he hit my sister. this time he is not violent but i am scared. and want to do my part carefully. so please suggest me that how should i talk to him.