Reunions usually involve many different activities. Maybe choose just one or two and fill your other free time doing things you would normally do on a vacation, rather than all the reunion stuff.

You have permission (from the Universe) to not go. But... if your friend has any understanding of your traumas... she might be a good support person to try this with? If you do go, can you make it an event that YOU construct, or will you feel swept along from one thing to another by your friends or the schedule? If the latter, I wouldn't go. If you can be your own person, and plan some truly fun things also, then I encourage you to go.

TC!