I want to repent but is it time? ?

Hi, I am becoming more and more closer to God. I have had premarital and I feel bad! I pray to God for forgiveness but I find myself repeating the act. Please help me, this is hurting me on he inside but I dot think I will be getting married any time soon! I don't want God to be disappointed in me but I just do not think I can stop having . I am not going to be baptized unless I know I can keep my promise to God. I fool around guys, give but only had "REAL 3 times. I am 16! :( I just don't know what to do! Serious answers only