student/soldier needs advice desperately please!!

Hi, early in the morning i backed up into my neighbors car the next morning
i woke up not knowing i did so because there was no damage to my car and
went to work. i seen my neighbor the next day and he said nothing to me nor
did he report that anything had happened. my girlfriend was at work and so i
left to work. the neighbor realized it last night but did not call the police and
report it. so today(a day later) he asked me if i seen anything. i said no
and called my boy next door and girlfriend to ask her if she heard anything. she then told me i hit the car and that i told her the night it happened when i came in, so she thought i took care of it because i went straight to bed. the cop came to my door as i was going out(not knowing she was coming
for me). and says did you hit this car last night? i said no and was going
to tell her it was the night before(just found out from phonecall to girlfriend and about to exchanging info with neighbor). but she whipped out a peace of tail light on the neighbors car from the bottom of my bumper where a small reflector is and was like dont lie to me all in my face and came in my house sayin license and registration following me throughout my house and into my back bedroom. and dont lie to me blah blah and was like i hit it the night before i didnt hit it last night. The last thing i remembered that night was wrestling with my buddy's and then waking up the next morning in my bed. my buddy said i got slammed into his coffee table. they said i got up all dizzy and sat down, and then told them i was fine and that my head hurt and was going home. since i never talked to my girlfriend till today(just before the cop came to my door) when asking her if she seen anything with my neighbors car and she said that i said i hit it and went to bed. anyways me and my neighbor have always been cool and we swapt information but the officer gave me a summoms for R.I. statute 31-26 4 which is a hit and run. my neighbor(with hit car) said he would come with me to the station if we could get it dropped but i don't know if i can because its not from him its from the cop. and also i had the insurance policy number but not the card and she said she is mailing me a citation for that too. im just wondering what i should do and what to expect. im a full !time student in the military and want to become a military officer and cant have anything like this on my rec. also like i said me and my neighbor are cool and it was the cop that gave me this. also like i said sunday i went to work when i woke up and today i stayed home and this all happened. today is a holiday and i didn't go to the doctor's. i dont have money for emergency room due to books and bills. so im going to my regular doctor tomorrow because my head has been hurting. i said this to the cop and she said "what where you boozin?" she was actually very rude to me and my neighbor said she was rude to him.

gather up all your evidence and your witnesses and you should be able to prove what actually happened...be thorough.

there are no witnesses for the accident at all. it happened in the morning between 1 and 2 a.m. my head feels fine now and i still don't remember. the cop through at me "o you where prolly boozin" but like i said the morning after i saw no damage to his car so had no clue(way the car faces road) and my car had no damage except on a reflector that i didn't see until pointed out. I went to work and he never reported it for a day later.

Well you will have to gather up whatever proof you can put together if need be.