anxiety and breastfeeding

So this morning we were going an hour away for a family event. We have a 5 month old. Usually not a big deal, but a few weeks ago my son completely stopped nursing during the day so I exclusively pump. Bringing all of the milk and pump parts and dealing with breastmilk out of the house is so stressful. It sent me into a full anxiety attack. In 5 weeks we are going on vacation and I am so worried about this whole pumping thing. I'm thinking about switching to formula. But first, I don't know if we can afford it, and second, I am worried it won't agree with my sons tummy. Any recommendations?