aita? boyfriend invited me to his friends wedding but i can't afford airfare

Just as the title says. The airfare is $500 minimum and that's with awful flight times and sleeping in the airport for one night. I'm an extreme introvert and as i'm honored he wants me to go, it wouldn't be so much fun for me as it would be an internal anxiety attack. He invited me to go and registered me as his plus one before i could confirm that id be able to take off work. I assumed he'd cover the costs of the plane ticket since he invited me, but that's not the case. He IS paying for the airbnb and rental car for us... but $500-800 for a ticket is just so much money for me right now. Especially for a strangers' wedding. I don't have wiggle room financially and he makes a lot more than I do so this ticket is just way out of my budget. Am i the asshole?? I feel like an asshole. He is really excited about this and even if i could afford it... ive been dreading it. Especially after finding out we are leaving the morning after the wedding and wont have time to explore the city by ourselves.