Would you leave your partner in this situation?

Heres the situation. Imagine you have been with your partner for three years and your relationship with them is mostly good. Your partner is already mentally ill but goes to treatment and usually takes their med. Then one day your partners best friend of 17 years commits suicide because their wife wanted to file for divorce. Your partner doesn't really talk about the situation because they think it would be disrespectful to blame their actions on their friends death and they seem to deal with the tragedy by becoming angry frequently and spending all their money on beer. They apologize for their actions but keep repeating them. They are never violent but seem angry and depressed all the time and are no longer fun to be around. They say they want to work things out and offer to go to couples counseling. Another year goes by and they still haven't changed. Would you leave them, or stay with them?