I don't think you are being at all unreasonable. She wants to have her cake and eat it, too. Married (or not) people who love and respect each other don't continue relationships with their exes, especially when their spouse doesn't approve. Lots of people still might, but they do it very discreetly behind the spouse's back (but that's a different issue).

She's gaslighting you by telling you it's your problem. It doesn't look good and I don't know if your relationship has much of a chance for happily lasting.