Let my life long friend's 17 year old little brother kiss me the other night when i was drunk, help?!?

Right ok so my friend ive knew forever (who is my age, 20 and male) and our mutual friend (who's 19 is another girl like me) were having a drink at HIS house (his parents were away) after id been to work all day. Id had no sleep the night before bear in mind. So I went they'd already started drinking and were at least 1 drink ahead of me so I poured myself a pint of mine and rank it pretty quick, felt fine. anyhoo over the next hour his younger brother who's 17 came in said hiya to us and went out the room. All cool, then my friend (the girl) went downstairs and was talkin to him while he was on the computer and we all get on ok anyway. I went in there and we were talking and drinking and after some time my friend the girl went to keep our other friend company and see what he was up to, anyway before i knew it i was pretty drunk and me and him had been sat alone talking for a while and just listening to music while he was on the pc and eating a pizza lol, he offered me some of it i probably should have said yeah and i might have been in a much better state later in the night. So i needed a cigarette and couldnt find my so talking him into saving me half (he had 3 in total, and we had to go outside for it) so we went out the back chatted fine and before i knew it it was like playfully chatting and flirting and he kissed me! (i was really tipsy though) and we were kissing loads it felt fun but risky as the others couldnt know and they could come look for us anytime. I remember our female friend came out and we were in a corner of the yard near the rabbit hutch and somehow we managed to make it look innocent ha..we all went in i was the last of us going up the stairs and he was touching my hands i think from behind his back as the girl mate was the first up the stairs. we all went in MY lad friends room and just sat around again listening to music and me and this guy were both in there (me still real tipsy) things happened, 3 of us ended up hanging in and out the 17 year old brothers bedroom. and he kept making comments that i was sleeping and staying in his bed and stuff. a couple of times we were alone and just kissed and i'm sure he had ideas to do more given half the chance but i wouldn't... and couldn't anyway as i was on my period at the time of all this. but i keep getting flashbacks of parts after this i dont know if he put his hands down my trousers which im pretty mortified about tbh but i vaguely remember him saying "theres no blood" and i said "there will be, trust me"...its so blurry and was the moment i woke up in his sisters room. There was blood on her dressing gown and i cant remember getting there or the last parts of the night. I went to bed alone but i dont remember or anything which is bothering me so much. it feels like because i know him i cant live with little parts of my memory on it being missing. I pass this guy atleast once a week sometimes more just going out my house. other than that im going on holiday with his sister in october and have to go to their house sometimes and its gonna be so awkward now if i see him there. Anyone who reads this what would you suggest i do or play it now? to stop any further embarrassment to myself or him really, because theres nothing i can do to change whatevers happened now. I dont think anybody else knows what happened like my friends or his parents im sure someone would have said something by now if so!! D: Any suggestions or comments or anything anyone? apart from stupid ones, tar! :)