She is equating love with someone making her happy. That's not love. WE all know that's not love. We know that love is sacrificial, that it costs, that it is an action not a feeling. But she doesn't get that - now. I thought she used to, but maybe she never has. If she just wants all the things and feelings she can get from this affair, I don't know that even the "best possible me" could tear her away.
So, considering all that, and since in her mind we are done, and we aren't legally married, and we don't have kids to raise together, and we're moving out of the house, and she's so "head over heels" with the OW, who she doesn't see any longer as an affair partner and instead sees as her "new" partner, and who is far more financially secure and stable than I am... how CAN I be her lighthouse?
I've struggled with trying to understand if what they have is love quite a bit. I didn't want to accept it as love, hated the idea. Parts of me realize if this was just a physical thing and it ended it would be much easier to deal with than love.
I don't believe it is love, not in the long run because we all have a better understanding of what love is now, and this isn't it. I do think they see it as love right now. I don't think that will always be the case.
I think most of our cases have similarities in their viewpoint, regardless if we are M or have kids. My W sees us as completely done, the D paperwork is just a technicality. Anything she does with OM is completely fine (even thought she hides it from me) since our relationship has ended. To her, its just pursuing the next partner. This is what they say and think for the most part, I still beleive there are deep down parts where they know the truth.
That's tough for being the lighthouse but its still possible. I would say in your case the best option is to get to a point where you don't react to her, don't get pulled into her arguments. You basically show her that you accept what she is doing because its her right to do so, even if you don't agree with it. Be strong and continue to improve your life in any way you can. Let her go, let her make those destructive decisions and maybe one day she will look back and realize you were the lighthouse all along.
And if she doesn't, so be it. You have made yourself so [censored] awesome it wont matter. There are others out there that can and will deserve our love. It will take us time, but in the end we will be OK no matter what.
Accept what is, let go of what was, and have faith in what will be