Yes, I felt the classic ILYBNILWY; ..., I failed to keep the necessary boundaries with someone. Now, thankfully, it went no further than an infatuation on my part.

It sounds like you were emotionally attached to this person, it is no wonder you have difficulties feeling anything for your H. Do you still work or have contact with that person.

I am choosing to put that behind me; I don't even want to think about it

Again, if you are still in contact with that person it might be tough.

God Bless