The idea is to not treat the game like a playground slide. Instead, treat it like a stairway. If you feel the slightest bit of confidence, in going up the next step, make sure you go slow and steady so you won't slip and fall.
What happened to me is I've been stuck for months. I think I made a tiny amount of progress the last few days but on the rank scale I feel like about an E-.
Ps. I love the Jessy Pokemon team rocket in disguise as a school girl avatar.