Dude, you really bought the tickets! Holy smokes!!

Way to go. I'm sure it makes your heart pound to think of the minefield you have to walk thru between now and then but you can do it. Simply tell her that you need your time to yourself just as much as anyone does, regardless of the fact that you have kids from a previous marriage and are a recovering financial dunce. And leave it at that. Stuff like this just makes her nervous because it triggers all sorts of abandonment fears that her dad set off, so try to keep that in mind and retain your empathy.

Btw, are you roasting today or what? (those cheeks are red due to the heat and humidity, of course)