Do I have to completely stop drinking ?

We decide this together .
This will also depend on which programme you are in. 

Do I need to be Alcohol dependent

Absolutely not.
We live in a culture where alcohol is everywhere and there are so many high functioning drinkers. However, you do not need to be labelled an alcoholic or alcohol dependent  for alcohol to impact your life .
We do know that alcohol is progressive , so if you are a binge drinker now , or have a daily drinking habit , then ten years down the line , it is likely to be worse.
Before you reach the stage of being alcohol dependent is a good time to change your relationship with alcohol. 

I drink because I have an underlying mental health problem ? Will it get worse ?

I have over 25 years of experience working in mental health . From working with people with psychosis , to anxiety and depression , to OCD and self harming . So if there is an underlying mental health problem , together we will find that out and get you the most appropriate treatment.
That is ok .
But until we control the alcohol we cannot assess the severity of other conditions that may or may not exist .