In my view, the choice is about whether you are better off with her or alone, including the financial implications of divorce.
While there may be "other fish in the sea", that is a poor basis for deciding whether a marriage is worth saving, and it will likely bite you in the divorce if it comes up.
Keep in mind that you will have to reconstruct your relationships with your family and friends along the way... which will likely be easier if at first you don't have a new partner.
Good luck!
I have no "proof of reality" to offer you (Plato had similar thoughts with his "shadows in a cave" analogy), but in all cases I have heard of pursuing these hypotheticals too far simply feeds neuroses rather than uncovering the Illuminati. The current US paroxysms of conservative conspiracy theories are IMO the product of failing to rein in such unproductive thought... do you really want to go down this road?
Your 26th century bit reminds me of the Continuum tv series. Entertaining story, but not likely to be worth building your reality on.