It took me 4 years to learn in school but most of what you are doing on school projects is your own doing.  When I started working 30+ hrs a weeks in an office in 3rd year I learned you can produce the same quality of work in a quarter of the time if you don't over think it and simply set goals.  ie in 4 hours this elevation drawing will be complete and in four hours stop.  You could spend 20 hours on the same drawing but you don't need to.  Its that way in the real world as well, you can work on a design or set of drawings forever if someone let you.  Its a little bit of blasphemy but if you want to game the system a little learn what your instructor likes and just feed him/her what they want, if life balance is your goal.  If exploration and learning is your goal then spend all your time in arch studio.  You'll never again be able to design with no budget, no client and very little rules, so enjoy it.     

Don't talk about what you had PLANNED to do and how you failed. I've seen so many students start off with "Well I was originally planning to do 7 schemes but..." Simply present what you have, be well considered, self edit, and go into it with your priorities straight. If the other aspects of your life are equally as important, rearrange your efforts and expectations to match. Then make sure you aren't constantly apologizing for only having one well considered idea instead of the 10 that your classmates do. 

Under-promise, over-deliver.