I've only had two really long travels in my life, and my best advice is resting after you arrive. Don't overwork yourself and try to relax as much as you can. You'll be okay, you're going to vacation to have a good time. And as far as I know, Italy is a beautiful place. I hope you enjoy your time there :)

What an amazing opportunity, I am so happy for you. Focus on the postive. What are you anxious about exactly? Are you going with a group or Alone? You have a travel partner that you can talk to about it and maybe develop a plan if you are feeling well what to do?

Oh my gosh you have what I have Cool. In a way

So when I travel I look up ER locations and figure out what my options are and do the research so I know what to expect if I have an emergency. Knowing what my options are puts my mind at rest and helps my anxiety. Feeling trapped or stuck away from home can be really scary. I have several times been traveling and had incidents then looked up where the nearest ER is and then imagined my self going there and then thinking “I am better off just staying here!” “I will get better in a few hours!” “If I don’t get better then I will go.” Most of the time I get better. I hate going to the ER. But sometimes it’s necessary. Like I have a very large 8mm possibly kidney stone. That at any time can drop and ruin my world. I have been there before. It’s the worst and recovering from surgery is really bad too. Okay, I need to stop thinking about it. Hope this helps. Do your research before hand so you know what your options are. Knowing this information hopefully reduces your anxiety.