If you can take Some Risk: Take admission in college, quit the job and work on your startup.

If not: The only key word is "Determination","Where there's a will, there's a way"

Still I have some tips for you:

1) Increase your physical activities(Imp), go to job and in night work on startup.

2) "Time is money", Move near to your work place.. etc

3) Live with your co-founders (or Girlfriend or Love ones)

4) Keep some spare time to meet your loved one, it keeps you motivated.

5) Focus on correct things, 80-20 Rule. 20% Task get your 80% work done.

6) Work with a velocity that you can control. One should know his/her limits.

7) There are points in time where things don't seem to be going well, in such times its only you who can help yourself. Be determined

:) Cheers & Best of Luck !!!Eat good Food :)