I'm in a pretty terrible financial situation right now (lost work due to illness), so that's a lot of money.
Jess, please don't go. I know you want to and I know how much you care. And I think those who are suggesting ways of cutting costs (carpooling) are being kind. But I have been in your situation where even one dollar makes a difference. So I say this with all kindness. Take care of yourself. Your friends, assuming they care about you as much as you obviously care about them, will understand. They will love a simple handmade card or a handwritten letter from you that wishes them well and shares some memories, hopes, and dreams. That is the best thing you can do for yourself right now, and I think that must be your first priority.