Want divorce with full custody of my 7 yrs. old daughter

We are married last 16 yrs. From 2-3 yrs my husband is quarreling with me for not giving sufficient time. Last 16 yrs. I am working in private firm as a Secretary & he is school teacher, however he is getting permanent & got salary as per 5th salary scheme from 2009, till then I was working & fulfilled all household responsibilities including his education (which he was denied). Last 2-3 yrs he was threatening me that, if I will not listen his he will kill my child & then he will be trying to kill himself also. Many times he was beating me & my child, also he was also frightening my child with knief, koyta like that. From May 2015 he is not doing anything with household responsibilities, only giving monthly expenses contribution (half). Also from May 2016 I am taking psychiatric treatment for depression. Now I want to divorce him & want my daughter full custody. Please suggest me what & how should I put my case? My psychiatric treatment will affect my divorce case & custody case?