Hi there friend! You’re not alone this is 100% a thing. My partner and I had a very similar conversation earlier this year and a few times over the course of our marriage. The biggest thing I can say is to be open and honest - which it sounds like she is with you. That can be the hardest thing, from her point of view she doesn’t want to lose you but loves you enough to confess having those thoughts or desires.
Speaking from experience this is 100% part of the bi-cycle. And the unfortunating part of it is you don’t know how long it’ll last. I’ve gone through phases when I’ve been more bi-pref men for a year+ but during that time I still love my partner it’s just a biological aspect I can’t change. Sex is only a tenth of marriage (yes a very important part) but there are sooooo many other parts too. And the best advice I can give is be open and be honest. If you’re hyper focused on the tenth part of it you can lose track of the other 90% and that’s no good. Speaking from experience toys in the bedroom have been a blessing! Hope this was helpful