friend booked this without asking me

hi so,
she asked if i wanted to go to reading festival and i said i cant afford it and i only know two artists per day.
i didn’t say yes or no. i should’ve said no so it’s my fault and if she told me she was gonna book i would’ve said it!!!
we were just messaging about it and she then said she booked it…. she’s paying for my ticket which is lovely of her but it’s far too much for her to pay and i’ll still have to pay for travel & hotel won’t i. it’s also not long before our holiday together too. i wouldn’t enjoy going as she’s picked a day she’ll love to go to but i don’t like many of them on that day. it’s nice she wants me to go with her but now i feel like im in a sticky situation because i don’t want to waste money on travel when i dont want to go.
what do j do? shes only paid for hers today and she’s paying for mine tomoz. ( she’s doing it monthly )
do i have to go now as i feel so bad ?? i should’ve communicated better????
not sure what to reply with! please help me.
i am so appreciative don’t get me wrong and it is a kind gesture for her to do. i would enjoy it if i knew more artists but she knows its not my cup of tea.