i understand where you are coming from, as my parents have told me the same thing at the age of 18!
the thing is our elders see religion as something you should HAVE to follow and that in a way i think they are pushing it upon us. i believe that to be a Sikh you should be pure in your soul and eventually all people see the path to taking amrit which will lead to all the 'right' things coming into place.
when i spoke to my parents about cutting my hair, i received an ultimatum, if i cut it, i am disowned. this i think is a harsh reality as my father used to cut his hair and never had such restrictions upon his life. the fact that my parents have given me this ultimatum has meant that inevitably i am being pushed further from my religion. this is hard to do as i have grown up with kirtan and sewa etc in my life, yet when i chose the path i wish to walk i am oppressed and looked down upon.
although i have not cut my hair at present, the thought is always in my mind. yet, i have taken it upon myself to see what i think in a couple of months to years about seriously cutting my hair, as the tradition of doing right by the family is a 'burden', in a sense on my shoulders.
my advice to you would be take your time, think seriously if this is what you want to do and i hate to say it but think how it will affect your family.

may waheguru be with you, no matter what road you chose to take