It sounds to me like the alcohol is the root problem. She may fear that you lack guiding principles (especially without religion) and takes the alcohol as prime evidence.

She wants the best for you and fears that you will not work hard towards becoming a strong member of your community or family unit.

If you want things to be better you have to commit to change. It's OK to not be religious. It's OK to drink alcohol. But it's not OK to bring it into her house.

Do as well in school as you can. Find other ways to help out and be productive, make it routine.

Above all else, forgive them if they wrong you in the days to come, prove that you can be the kind of person they hope you to be, religion aside. Give them a chance to accept you once you have shown there is nothing to fear.

Things look bleak now, but in a few years you may look back and say that today was the day you turned it around and saved your future. This trial will be forgotten.