I recommend using the "Important vs Urgent Quadrant" which is a square chart you can easily find online.
Every author has a different flow and schedule to time and release their works, there is not a system that works for everyone. I'm also a uni student and have a full time job, as much as I like writing it's not feasible all the time.
TO prevent myself from going too far in one things I try to organize what I want/need to do in those 4 squares.
Quad1: Urgent and Important - (Do)
Quad2: Not urgent and important -(Plan)
Quad3: Urgent and not important -(Delegate)
Quad4: Not Urgent and Not Important -(Eliminate)
For writers we often feel that our work is urgent when it's not. It is important to us personally but often times not 'urgent' often then writing goes into Quad 2 and 3, sometimes even 4. When you have time and nothing else in Quad one of things that need to be done in your life/schedule then work on you novels (often Quad2 & 3. So you should PLAN and DELEGATE your writing/posting schedule).