About to be arrested?

A restaurant I was previously employed at accused me of changing credit card tip amounts and filed a police report. Initially the police said it didn't look like anything and not to worry. That was a relief considering I did not do such a thing. After about a month an investigator called me and just recently he left me a voice mail saying he was about to forward the matter to the state's attorney and a warrant would be issued. Now, I thought that since I did not do this I would have nothing to worry about. The fact that he claims to have enough 'evidence' for a warrent really worries me. I have a great job and a pretty great life, I dont want to risk going to jail and having to pay bail/bond, not to mention humiliation. I just don't know what to do. I looked over the receipts that they claim were changed. It's hard to tell if they were or not, like noticing the difference between a 9 and a 4, etc. There were a few that were written over. The hard thing is that since this matter seems to have been in my benefit it looks like I did it. I've always been upfront about the situation and said that if I gained money I didn't earn, I dont want it and if there was some sort of mistake I will gladly pay it back. I guess nobody wanted that and wanted to make things harder for me. I just don't know what to do. I spoke with the officer today and he said he's about to file charges for 9 felonies. If i 'cooperate' it could be brought down to a few misdemeanors. I don't want to admit to something I didn't do, I just dont know what to do. I dont want to be arrested, I dont want to feel scared about being punished for something I didn't do. Overall I'm just so confused. If anyone has any advice, I'd gladly appreciate it. My boyfriend says that the investigator was probably just probing me to admit to this and that it probably wont go far at all and not to worry. I wish that were the case, but since it leaves the possibility for me to be arrested i have a lot of worries.
Anyway, I think I've explained too much, ha. So if anyone could please offer any form of advice, I'd really appreciate anything.
Thanks.