I legit don't understand how people can complain about money and yet worsen their financial situation by choosing to attend an anime convention. Dude... just, what the fuck. Get your finances and life together first before you decide to take a nerdy weekend vacation. There are far more important things here that don't include feeding your mental escape and temporarily providing "healing" for your depression (that will for sure get worse when you see your bank account post-con and are jolted back to the realities of adulthood).
Like, shit. I've been struggling with depression since middle school (and badly, at that) so it's not like I can't sympathize but sometimes you just need to suck it up and attempt to be a responsible adult. Both new and old anime conventions will still take place every single year of our miserable lives, so it's not like they're going anywhere. It can wait until you're financially stable enough that you can spare the expense without worrying too much about it. It can wait.