TweetLife is to short for this stuff brotha!! So anytime she hears something from here on out she is just going to believe it?? That isnt who you should be with. BUT if you TRULY want to make it work, just explain yourself and give her space to figure it out. I have been in your shoes and I did just that and it ended up not working out in the end because I couldnt believe she did not believe me. Even if she decides in a week or so to work it out, you might have some resentment towards her and will have future issues.
I can only imagine your frustration cause I have been there. All you can do is tell your side and let her figure it out for herself. Because more you plead your case the more she will push back imo. There are alot of haters out there who want nothing more than to bring other people into there misery. My advice is to let it go for awhile and see what she says in a few days. If she still doesnt believe you and wants it to be over then part ways, cause you shouldnt have to defend yourself to someone who is supposed to care about you that much. There are more girls out there and ones that communicate better and stand by your side when shiit like this goes down. Best of luck bro and dont stress too much cause you can only be yourself and cant control situations that are out of your hands.