can’t access site or admin panel

i made a HUGE mistake. in trying to make my blog title link to my first page, i went into the general settings – and replaced both addresses with the address of my first page.

i can no longer access my admin panel, and my site looks horrible… all the changes i made are gone.

what should i do?

thanks,
aida
ps. i’ve looked into other inquiries like mine, but i don’t understand where to go to make changes.