tea is the best replacement for me. non caffeinated tea at night with just a bit of sugar or honey.
as far as quitting, you can either try going cold turkey or slowly ween off of it. experiment with both methods.
weening off of it works better than going cold turkey imo. what you wanna do is limit your drinking sessions to once a month and after that session, don't drink for another 5 weeks and after that drinking session, don't drink for another 6 weeks etc... and keep increasing the pause. before you know it you don't even wanna drink anymore.
drinking only once a month is fine too.
drinking once or twice a week is way too much. as you'll feel shitty all the time, tired, depressed, anxious, and unmotivated.
you want to use your weekends wisely to get ahead in life financially or with school.
also someone already said it, try changing your environment as best as possible. your current environment of stress and suffering is causing you to drink away the pain.