I am a hand quilter also and I have tried several brands of quilting needles/betweens. Some become dull very quickly, others you can use for weeks or even months! Unfortunately I don't know the Dritz needles, obviously they are not available here in Germany.
What you describe sounds to me like a problem of the way you have the quilt in your frame and how taught it is. Feline already mentioned that. Try to put your quilt in the frame more loosely, that might help. I quilt in a hoop on a stand and I put the quilt in exactly like feline described it.
Another reason could be the quilting method you use, how you guide your needle and how much pressure you put on it. Roxanne needles and also the John James brand are quite strong and they don't bend so quickly like others.
What kind of batting do you use? Some battings needles very easily, for others you need much more strength to needle them.