Trapcode Particular streaklet becomes choppy?

Hi!

I'm very new to trapcode particular, so this might be an easy fix, or impossible! 
I'm trying to animate some light streaks in a wavy shape. I want the ends of the wave to be thicker, and the middle to taper down, as if it's a light trail that rotates. The problem that I keep having is that whenever I either change the size of the particle (streaklet), or if I use a custom made sprite shape and rotate it, the lines become choppy. I've increased the particles/sec, and it was smooth before I tampered with the size or rotation. I've chosen a point light as emitter type. Is there any way to fix this? 

Getting desperate, and I would be eternally grateful for any help!