Hi
stellamath and welcome to GMAT Club!
I am sorry about your stress levels and your professor. That seems like not an ideal GMAT Studying experience.
I was able to restructure my day to get the best time to focus on the GMAT during the morning hours and then coast at work. You want that type of environment rather than a high-paced and very stressful time when you can only study during breaks and after dinner - that's not going to get you far.
Unless you are able to get a solid stretch of time (a few months) and get quality time (most likely morning if you are a morning person), I would say it is going to be wasteful and frustrating. Depending on the score you need, you may be able to study for just a month but most spend 3-4 months to improve 150 or so points with diligent studying.
Hope it helps.
BB