Don't use Photoshop for inking. It wasn't really designed for it and as you've discovered, you'll have to really wrestle with it to get results.
I know you said you're broke, but scrape together $50 and buy the debut version of Manga Studio. It's a program specifically designed to simulate inking and it does a damn fine job, IMHO. It has adjustable levels of correction to smooth out your brush strokes and is generally very user friendly.
Just my humble advice. Mileage may vary.