And individual therapy would be a perfect and totally private outlet for your needs given that it really isn’t a good idea for you to tell friends about this or how hurt you are (friends can be really judgmental with these things and telling them puts them in an uncomfortable position and will be embarrassing to your husband). Also count your lucky stars that your crush doesn’t reciprocate, I mean your situation would be a million times worse if he did!
But you will have truly given your marriage a shot at being the great relationship, which is what I personally think marriages deserve
As you’ll see, I agree with those saying that this is like an addiction. When I was in the situation, that’s how it felt. Almost nothing but time can help. But one thing you might try is reading forums about the aftermath of an affair, like Surviving Infidelity. It will be something of a dash of cold water. But it will show the sheer amount of work that you’d end up doing to repair things if an affair happened (and by your statement about him on your doorstep, I kinda think you’re playing with fire here).