Emotional detachment makes sense if you are not able to separate.
However, two points to consider:
1. How do you envisage this relationship long-term for you? 5 years down the line? 10 years down the line?
2. What is the impact on your kid? Kids imbibe what happens in their environment and use that as a model of how to 'be' in life - e.g. it is okay to drink too much, it is okay to stay with a partner who drinks, it is okay to stay in an unhappy relationship etc.