Well good job on those four days. Everyone starts someplace, and I think most people have some good days and some not so good days, but you keep working at it and it comes together. It's a process with a learning curve like anything else.
I used to just try to get more days sober than not sober, and those started collecting in bunches, and then it was weeks sober, and months, and now it's hmm fourteen? months .. so yeah it can take some time.
Good luck on grad school!