Re: Am I a terrible drummer?
Zurg, I only see challenges in your OP :)
3 years drumming is not what you'll call a lot of experience, so it might be quite a few things to look at...
How do you project yourself? your attitude towards your band mates, the director and the music might need a different approach?
Take the challenge to play Ringo's parts as close as the records as you can, it's easily said, harder to do, try to capture the feel. Do not overplay and do not add your own things/patterns while playing the songs.
Work and practice those songs at home, really hard, so on your next rehearsal, the director should see some serious improvement, that should get the "dedication" part solved.
I have not seen your setup, but set it up as conventionally as possible, beginners and young drummers tends to have strange set up. Is the tuning of your kit OK?
Last but not least, ask your director for advices, directions, etc... he/she will like that.
Here you go, if after genuinely applying all the above, your director's still not happy with you, then it might be something wrong with him/her.
But I'll reckon you'll be alright, swallow your pride and ego... and go for it :)
Let us know how it goes.
Keep On Drumming