It's ok to miss someone (and even love someone) that you don't want to be with any longer. You probably ARE confused. I think breakups can really pull some emotions out of us and make us second guess. It seems to me that possibly a divorce could be like that too. A breakup on steroids. Because it takes longer and you have to do the legal thing. I can't tell you what you should do, and you probably are experiencing grief and I know you said guilt. You sound like a good and kind person. The fact that you said you also feel relief about her signing the divorce papers though, is telling to me.

In terms of the woman you are seeing right now, it sounds great and very promising. It sounds a little like you are really kind of stuck on your ex because you said you don't feel love like you felt for her. I wonder if every relationship is a different kind of love. I'm not that relationship experienced to know. But you might need to take it slow with new partner / lover, to get your head straight.

In terms of missing her VS just remembering her, maybe it's both. and maybe that's ok. I had a conversation with someone recently about how toxic people, are not always bad people (though in the past it sounds like she was not very nice to you at times). And what toxic means, is just that someone isn't right for you any longer.

Trust your gut. You are having a lot of emotions right now, but you will be ok.

I see that you responded to the thread, but hopefully this is helpful somewhat.