My MacBook stops suddenly even after resetting SMC.

I have been trying to turn my MacBook on for the last three days, it works sometimes and sometimes doesn't, I tried resetting the SMC too and it doesn't work. It's charging properly and the SMC command works fine (the charging light turns green for 3 sec. When I give the SMC command). Do I have to come to repair shop and what are the possible causes for this problem. I am currently a student and my studies and other important projects are dependent on my laptop, need urgent help!!