Thanks for the update. I'm glad you got to spend that time with the girls and the trip sounds amazing. Like Ovrr, I have always wanted to go to Central America and would love reading a little more about your trip.
I am not surprised your emotions are a little all over the place. It's like having had something to look forward to for a long time and then once the thing you were looking forward to passes, your left with that empty "What now" feeling. The January blues amplified. That feeling once christmas and new years are over, it's dark and cold outside, you have to get back into he work thin and it just feels like there is nothing left to look forward to. But the sunshine comes back, you plan your next holiday and have that to look forward to, you get back into the routine of work and then the feeling passes.
I get that you feel more centered when you don't see your XW. I see my H all the time and he still has the power to throw my emotions (less now though) but that has only come with time and practice. I can switch off certain parts of me because I have learned to. If you rarely see your XW then your body probably goes into a little bit of shock and all the old hurts come back. NC is probably a good idea until she loses that power over you.
Are you seeing your girls for their birthdays? Where are you going to put the next tick on your list of countries visited?