This board too small for me?

Hi, I'm pretty new to surfing and was wondering would a 6'0 softboard be too small for me. I'm 5'8 and weigh around 122lb. Also as i am a student i wont have enough money to purchase boards over $AU200. Also i've done several lesson and have been able to stand up and stand on it until the wave dies out, however this is only on the whitewater bit of the wave. Now i have another question... everytime i try to catch a unbroken wave my boards nose most time seems to dip into the water and therefore i wipe out. Any suggestions on how i could fix this problem?
Thanks in advance
Thanks in advance
