Suggestions? Learning but I Can't Fight This Habit

[Rocklobster]

I love playing rhythm guitar!

I need some suggestions on what I can do to stop my current technique of playing. After months of playing I am still struggling to bring myself to use my index and ring finger to bar power chords on lower frets. I'm finding myself ALWAYS using my pinky when it comes to the lower frets (which limits me to a 2 note power chord instead of 3). I find it a major stretch for me to use my ring finger alone or along with the pinky for the top two strings on power chors on those lower frets. Am I not curling my wrist enough when I play to let me get that stretch? This "Stagemaster" Squire is the only thing I've used since I started learning and I read that Gibson type guitars are usually a little better suited for people with shorter fingers as compared to Stratocaster type guitars?

Here is an example of my delima. I am playing along aloud with my PODxt. Another issue is I am striking my nails on the strings rather than using a pick (no there's no pick in my hands there!). Anytime that I use a pick I can't differentiate between the strings for some reason and I feel without using a pick I'm losing out on a fuller sound.