What If I Really Do Just Suck?

I'm working through this artist's self-helpy kind of book (which is so so so so so so so so not like me, but I'm really trying to find the key to why it is I haven't accomplished what I want to accomplish in my writing, plus there's an online group I'm hooked into that's doing it, so I'm there) and one of the early exercises in the book--it's The Artist's Way, which about half the people in the world have read and done, I know, I know--directs me to think about where my artistic/creative 'blocks' come from, and then to do all these sorts of exercises, affirmations, writing of letters to the mean teacher who told me my writing sucks (which didn't actually happen, but just as an example). And while I'm all for people ridding themselves of negative self-images, of outside influences telling them what they can or cannot do, there's something that niggles at me here. And it's this:

Isn't it just possible that some or all of the negative things I think about myself are true?

I mean, not every person in the world is a good writer. You can positive-self-image yourself from now until tomorrow, but if you ain't got it, you ain't got it. So how much good is it going to do for me to talk myself out of believing what my fiction-writing professor in college said to me about how I had to develop my own voice, that I had a habit of taking on the voice of whoever I was obsessively reading at the time, and that I needed to find an authentic voice of my own...how much good would it do for me to do the whole Stuart Smalley "I'm good enough, I'm smart enough" thing if what that teacher said is true? What if fiction writing is--as I have this sinking feeling it is--a waste of my time? What if I really do just suck at it? What if nonfiction is where I need to be putting my efforts?

I guess what I'm saying, in both a larger and more personal form, is that I do think there are people who are just Not Good at writing or at certain types of writing, and I'm not sure anyone is doing them a great service by banging into their skulls the mantra that the only thing holding them back is their negative thought processes. I think I suck at writing fiction, mostly because my imagination is limited, and because I can't write dialogue to save my life. Now, if these things are true...should I still be pursuing a dream of writing a novel, or should someone slap me across the face and say, "Snap out of it! Do what you're good at, and stop pining over the things you're not!"

Which is not to say that I'm not going to write. I'm a writer. I am good at some forms thereof. I'm in no hurry to quit. I'll even consider that I'm wrong about the sucking-at-fiction part. But if I'm not? Then I really think I'm just wasting my time blaming my lack of creative progress on people who told me the truth, rather than blaming my lack of creative progress on my creative suckage.

[And on a completely unrelated note: It's 'only' going to cost $200 to fix my mirror, which is better than I'd thought. Haven't heard yet from the owners of the car whose mirror I also broke, but I'm hoping that it won't cost them much more than that. That will hurt us financially, but it won't kill us.

And thanks for all the commiserating stories. Who knew there were so many people whose years get off to such a crappy start?]