Any tips?

I'm newish to this site. I joined before, but never used it. However, at that time, I weighed 150. Now I weigh 170. I've been constantly stressed about university, and I've also recently quit smoking....which means I'm eating a lot more (mostly fast food, cause I don't have time for meals). My goal is to weigh between 120-130 pounds by New Years (which means I have 5 months to lose at least 40 pounds). Once I start university, I will also be going to the gym more, and exercising more.

Long story short, does anyone have any tips to help me out? Thanks! ☺️