Should I go to the music festival?!?

I went last year and loved it, but it's 4 days long and it is 'hard work' having to last camping in muck and rain etc, but not many are going this year and 1 of my friends is, and he asked me would I and I said yea sure I think I will, and now it's in a few days and I've no ticket/transport to it etc and amn't sure if i wanna go, but I'll be letting him down as he has all his stuff sorted. I know he knows others going as he is on a booked out bus to it, but he asked would I and he's counting on me I think. He text this morning and I didn't tb and I saw him then today but he was far away and I didn't say hi, though we both know we saw each other! I still do wana go on some level, but I'm just not too pushed. If I do go I'll be glad I did I'd say! what should I do, go or not?!