I'm sorry that Valentine's Day was rough. We all had a discussion of what a stupid holiday it was. Anyway, maybe next year will be better.
I'm glad to hear you use the word grieve. I was concerned that you would think/logical your way through this process and miss the very real growth that can occur. Of course, you must grieve. Of course, it isn't exactly about the actual person but it is absolutely about the false view we had of that person and even about the false views we had of ourselves. And of course, the plans and goals. Weren't we supposed to ride off ito the sunset together? I think you are doing wonderfully.
The grief stage is not endless. It does pass and then it arises again at weird times. I had this bizarre sense of guilt when I started dating again. Felt like I was cheating. Had a need not to talk about my new R with people who I normally would - my Mom, my best friend. I didn't want to share it with anyone. I felt as if it could be jinxed somehow. I had to revisit some of the grief during that time too.
My point is that there are a series of stages and you are doing just fine. I'm glad you are seeing friends and I'm glad you are still keeping up with us hopeless cases (mostly me).