In my opinion you are still to young but thats just me. I am 5'6" and 165 and still thinking I am to thin. I know how you feel though, I wanted to start a cycle so badly when I was your age but I honestly think its in your best interest to wait. I know you probably don't want to hear this but eating right and training right are your best options right now. Some will probably disagree with me but I am sure many others will agree.