It's obvious how much hope and planning you've put into a future together. Your instincts are correct though, paying for her party won't help either of you.
She can't feel independent if you are paying her way and you won't respect yourself if she's walking all over you and crossing the line with OM. This changes the "deal" you had when you agreed to financially support a confused, space-seeking wife trying to further her education. I honestly can't see how this can help you achieve the goal of creating a happy and healthy relationship.
She may very well be depressed -- OM is usually just a bandaid to cover up something she thinks is missing. She may very well need help, but keeping her financially dependent upon you, when she is on the verge of losing you, isn't really going to help her.
There is more to life than putting one foot in front of the other, JWS, and you said you have too much "down time". What kind of puppy do you have? What kinds of things do you like to do for fun outside work?
Is your C helping you figure out changes you can make for yourself that may have contributed to the problems that led up to her leaving in the past?
I'm sorry you had such a rough night. They can be brutal; the kind of pain you're in is unforgettable. For now, surround yourself with people who love you... and your puppy... and let them comfort you until you get to the point that you can learn from it.
