I agree with everyone, maybe you should try to go down a level. That would put less pressure on you. It's true that it is hard to commit to the challenge but I am glad that you are taking it on. It's okay to take a break every now and then. Think positively. Maybe later you'd get back into drawing and can quickly catch up :)
Don't put too much pressure on yourself. Do what you can ^^
Good Luck!
Best, P-man

I agree with what everyone below is saying about dropping down to level 2, I think that it would definitely be a bit easier to do. Doing a drawing everyday is a pretty big challenge, I'm not even sure how to avoid an art block for it.

A couple of things I can suggest would be to draw your favorite characters, so that way it won't feel like you're drawing random characters, you could even do repeats of the character in different poses?
Also depending on how big your paper is, you could fold it in half and just draw on half a page for each week? I use regular copy paper (8 ½" x 11) and I've been folding it in half and it's been working well so far and I don't have to draw too big and I'm not feeling to pressured.

I also don't think you're letting anyone down. It will just take some time for the event to click with you. Just remember that you are doing this for fun.
Also if you want to just draw for your own personal things, I say go for it!

*gives you a pat* Don't get so down on yourself. I know I couldn't keep up with a drawing a day, either. As clue and elricz have said, maybe it would be a better idea to go for level 2 to give yourself a breather.

*HUGS YOU SO HARD YOU REGRET SHARING*

Keba, you haven't let us down! Now, I can't vouch for whether or not you've let yourself down *shot* but let me remind you that 365 days of drawing is daunting, tedious, and INSANE a very difficult challenge. Why don't you just drop down to level 2? Granted, I'm like 5 weeks behind on uploading but still. One per week is much less of a hassle and that leaves you time to do other artwork. Then you can do those things like color and draw other subjects and draw digitally (though nothing's keeping you from doing your sketches digitally).

I dislike the phrase "giving up", because technically, you don't have any ups to give! And who are you giving these ups you don't have to? It's very mysterious, if you ask me. I suspect there is a conspiracy surrounding what whomever receives these ups does with them. It's all quite shady. *looks around shiftily*

And for the record, we can almost never win with ourselves. It's a constant struggle to always surpass our own expectations... but you've gotta remember, there's no such thing as perfection. Just not stinking. And you don't stink. I can't actually tell through this computer, because your nice Keba-smell is overpowered by the scent of Rapidly Becoming Outdated Technology, but I just KNOW.

(I sincerely hope you had a good laugh.)

Why not drop down to level 2? No one is upset with you dear. I think that it would really help you relieve some stress on you and you won't feel so down.