Question for Hijabis

I have a question regarding my hair and my wearing of hijab...I don't even wear it full-time, yet I'm already noticing hair breakage at my hair line (like, where i once had some tiny baby hairs I now have many more and they are longer, thus, it's only practical to believe that my hair is breaking off). I know that this must be from hijab, because I have changed nothing else about my hair care, actually I recently got my hair cut off, so my hair is much healthier than it has been for awhile because I no longer put it back in a ponytail all the time.

I wear a white cotton underscarf seen here: http://www.middleeasternmall.com/white-cotton-hijab-tube-p-1339.html

I wrap my shaylas tightly over the underscarf, but I thought that my hair would be protected by the underscarf? I don't have a blow dryer at my husband's apartment, so I often throw on my hijab over wet hair...do you think that could be the problem?

I love wearing hijab, but I feel I must be doing something wrong for this to already be happening with me not even wearing it that often. I wash my hair every other day, and sometimes daily because it gets sooo greasy sooo fast.

Any advice? Anyone shared this experience?