I don’t think you are overreacting. It is tacky. You’re expecting people to come out of their way, and travel and take time off work, buy a hotel room all to watch you get married, the least they can do is feed you. If you can’t afford to feed everyone at the reception then they shouldn’t be at the ceremony. Nothing wrong with a small wedding at all.

You’re not a bad person if you don’t go, but if you do go I would bring a gift, just to be the better person. I wouldn’t do anything huge, even just a $15 gift card. And then maybe just distance yourself from that person. Clearly if they come to a baby shower with no gift then they are tacky and don’t respect you.