An annulment is not going to get you considered "scripturally free".
If you had sex with her - your stuck.
If she fooled around and that's why you got the annulment, she would have to confess, then the marriage would be dissolved in a way to make you "scripturally free"
If you screwed around and she didn't, then she could divorce you and both be free but you would probably be DFed for Fing around.
There are NOT enough details to make a call here.