Not a 3b/c, but my hair does that. I think that alot of tighter curlies experience that. Especially with more length. I just deal with it. I can be frustrating when you want a more uniform look, but after awhile, it becomes pointless is trying to make your hair do something it doesn't want to do. I just work with what I'm given, and am pretty happy.
Including length pulling the curls into waves, hard water, certain products, environmental stress, etc., all of these can contribute to differences in curl pattern(oh yeah, and genetics).
I don't think the varying degrees of curl look stupid. I hope not, because if so, I must look like a fool all of the time then.
The only thing I can suggest is maybe doing twistouts. This is really the only way I can truly get a uniform look. Product wise, Curls Whipped Cream
gives me a pretty uniform look. Not completely, but it has made a difference.
I'm sorry to hear that you are frustrated, but I'm sure your hair still looks beautiful. Un-uniform curls and all.