Plz help me...my whole lyf depends on dis...?

i m in 12th science. Nxt yr i m gonna appear for some entrance exams n i m in a big problem on dis stage...i dont know wat has happened to me bt i hav lost my focus on studies, unfortunately. 1 year back i nvr thought dat i m studin coz later on i ll hav to earn my living i used to study coz it was my passion bt nw i hav adapted to my surroundings n became money minded...may b dis is d reason i hav lost my INTEREST in studies...plz help me focus back on my studies