Help me plz :( I NEED MY BOO BOO BACK?

i lied to my gf constantly but i havent gone behind her back to meet any girls up i aint proud of lyin to her and all i wanna do is show her tat i do mean it tat i wont lie anymore i no they say once a liar always a liar but i am gonna change and i dont lie for the fun of it i lie when i get scared it jus happens i dont mean to i been doin it since i was a kid as soon as i get scared i lie to avoid an argument or fite :( i have changed and i no tat the truth is betta then a lie but she dont believe me now becuz of my lies theres this girl tat asked me out while i was with casey and i turned her down she sed she likes me alot and she wants to be wiv me and told me to leave casey and choose her but i didnt i choose casey but wot happened is i had ma accident and i foned casey to tell her she was like worried 1st and then i put th fone down and ed i call u back i call her back and she put the fone down on me sayin im busy she was talkin to tat girl tat told me to choose and tat girl was sayin oh he linked me up and kissed me wen i aint done nofin like tat i havent gone behind casey's back yea i talked to girls and texted em but im sorry 4 tat i miss casey she sed its over but i carnt let her go :( i no i lied its a bad habit i dont like doing it but i wanna change i jus want to start fresh a new start no lies no past or anyfin i jus want a better future but all casey wants to hear me say is yea i did do it wen i didnt but she dont believe me cuz of ma lies but i wanna tell her the truth but she dont wanna listen i do love her and i do want her i wanna show her i have changed and even if it takes me years to prove it im willlin to do it cuz i love her but she dont see tat yea i hurt her and i aint proud of it i hate myself for it :( but i also done so much 4 her made sure she had the best time been there for her wen she was ill and wen she needed somefin i tried and i still will i aint proud off ma lies but i wanna show he tat i mean it i have changed wot do i do :( HELP ME PLZ :'( the problem is she is telling me to prove it tat i didnt link her up or kissed her how am i suppose to prove it i carnt go back in time but she dont believe me because i lied to her befor but this same girl was swearing at casey calling her names and crap but she is taking her word over mine :( i asked casey to tell her toprove it but she said she carnt so wot do i do i havent met this girl but casey wants me to prove it i no i talked to girls and i aint proud of it i no i lied but i didnt do it on purpose i hate ma self for it but 1 thing i havent done is gone behind casey back to meet some girl but she dont believe me all she sez is prove tat u didnt wot do i do how do i prove it cuz i love casey she sed its over but i carnt let her go i look at our pics 2gether everynite and i cry to sleep i love her and i need her i just want to start fresh just me and her i wanna show her tat i mean it wen i sed i have changed and i no its best to tell the truth then to lie :( I LOVE HER AND I NEED HER I JUST WANT TO SPEND MY LIFE WITH HER BUT SHE SED SHE ONLY WILL IF I CAN PROVE TAT I DIDNT HOW DO I DO TAT I CARNT GO BACK IN TIME :( :'(