I moved this to the N-400 discussion area. I don't see an issue with your N-400 filing, itself, under the 5-year rule. The underlying I-751 might be an issue. Is this a joint I-751 or did you change to a waiver since you are no longer together? You could change to an I-751 waiver at the interview, but be sure to go well prepared to show you entered the marriage in good faith.