Can somebody talk to me please? I need advice so bad!?

Yesterday had to be one of the worst days of my natural life! I can't believe i did that! I betrayed my family's trust when i promised ever since i was a little girl, i would never have ! my grandma always told me to wait! because we live in the ghetto, and there are young girl's having young, women having children and i said i would never wind up like that! my grandma raised me when my mother wasn't always there, and everything she did for me, she went through thick and thin good times and bad she broke her back to give me everything i wanted!!!!!!!!!!!! and i go and do this??!!? i felt TERRIBLE yesterday!!!!!!! like everything was all my fault!! but it all started when i was shopping for the holidays at Wal-Mart, and there's this boy that goes to my school, he called me while i was in the store, we talked, and he asked if he could come get me, as stupid as i was at that horrible moment, of course i said yes! we left from the store, he said he was gonna come out to get me, i said ok,so while we were heading home my mom and her fiance gave them the directions and everything because i just had to lie and say it was my friend and it was a girl from school! they believed cause he pretended to be a girl! and while we were driving he called and asked for the directions back and fourth ever since i got home, everybody told him where to go and everything, then my grandma asked me who was my friend and i told her it was a girl of course and she believed, she said she wanted to see him, and i said, no! it's one of my good friends! and she said i have to see who your getting in the car with, and i was like shoot! i texed him and told him, he told me what to say and i made up my own plan, i said i was going to the store, she said ok, so i headed to the store and i heard him yell my name, and he said he would meet me on 16th steet but he pulled up at the store i went to instead, so i got in the car, went to his house and we did the do! and he lived kind of far and my grandma and mom kept calling me and calling me and calling me leaving me voicemails saying this and that and yes i was worried! ever since i stepped foot in that car!!!! but i ignored it and continued to be selfish! and when we got done, she was calling, they thought i was at a friends house, it was late and they said they were coming out to get me, and i just kept telling them the same thing everytime they called!!! ill be there later im walking down the steet, and finally he dropped me off at the corner because he kept convincing me to say this and that, but of course i knew i was in trouble! i waited for a minute, then i got in the car, my mom fussed at me and said everything to hurt me so bad! i felt useless! she embarressed me and shouted at me when we pulled up at home in the driveway, she smacked me in the head, and i went in the house and sat down beside my grandma and she just spoke to me, and told me this and she wasnt gonna fuss and she would have a heat attack if she did! and when she said that, my body just froze and i didnt know what to say, my mom fussed at me and everything, and smacked me again and my grandma told her dont do that and she just kept crying and it was just so much to tell! finally my grandma told me to go take a bath, i did just that, and while i sat there....i just kept thinking what have i done????? it was dark and i just had to think! my mom came in and she apologized for everything and i told her i deserved everything that came my way! because there was no excuse for my dirty action i put this family through! she cried and i cried! and she kept telling me it was her fault because she wasnt there and so fourth and we talked and cried for minutes and she said she loved me more than anything else and she was soooo sorry! i told her i loved her too and i was sorry and she said it was not my fault and i was just in pain at that moment, and she left the bathroom and i got out of the tub, i heard grandma crying about my uncle because i seen the ambulance outside, he had overdosed himself from pills and they tried to revive him, his back has been hurting, because he just came from doing his time in the slammer, he had been in there for years and i wish to not talk about why, but its been years, and while i was in the bathroom, he said his last words, "your still my favorite neice" my mom was talking to me at the time, and he said you hear me and i wish i couldve answered, because now hes gone! he died while the ambulance took him to the hospital, i blamed myself and my friend called and she came over to comfort me and my mom did to, they said it was not my fault, i just felt so guilty, and i still kind of do a little bit, like im the reason for the pain, i just feel like i need somebody to talk to right now thats why im on here as silly as it sounds, yeah i know this is a long story! but it was a DAY! trust me! i feel like the worst person in history! i just don't know what to do! i really don't!