she told me she loves him more than she loves me.
I'm sorry about the trouble you're going through. Anyway you slice it, where you are now is a very painful place. It does eventually get better, with time.
The silver lining here, if there is any, is that your marriage has been relatively brief. That doesn't take much of an edge off the pain, but it does make things otherwise somewhat easier.
If she told you the quoted statement, and she was not just saying it for other reasons (and let's presume she was not), my guess is that the OM was "Plan A", but was unavailable to marry (already married to someone else), and you were "Plan B" (less wanted than Plan A but, unlike Plan A, available). At some point she may have wanted to cut it off with Plan A, but couldn't bring herself to do so, so she decided to be the OW to Plan A while marrying her Plan B so she could get both a marriage of her own and maintain her access to Plan A.
Do you know when the OM was separated? If it has been recently (last 6 months, given your schedule here), that may have also tripped your W into a mode of seeing Plan A as potentially more viable (due to potentially being available if he divorced his wife), which may also have motivated her to maintain the affair with Plan A.
Very nasty stuff indeed, really. Terrible, in fact. And terrible pain. But getting away from someone like that, as painful as it will be for you, is also much, much better for you in the medium term and beyond.