feeling low, depressed...help me?

please help me guys..i have my ipcc attempt after 1.5 months dat is in may..

i have been working hard ...(atleast i think so) bt some days u know i feel very very depressed when i talk to my friends who are in college(( speciallu delhi university)....i am an average student ..and fun loving .till class 12th i had so much fun bt now for ca i am into buks so much..pure din padhai n concentrating..
i sometimes feel bad , jealous and depressed too when my friends are having gfs and having fun..

how should i motivate myself when such kind of thoughts come in my mind..