If you would have landed in a wider stance on the last one you would have got it. I find it easier to 2 on to down rails urban style, but do whatever you want. Also, it's not a requirement. but being able to slide proficiently with your unnatural foot will help you.
Whenever I 2 on:
1st. I pop on and make sure my tips are over the rail if I'm hitting it urban style.
2nd. I do the motion for a 180 on, and look at the beginning of the rail.
3rd. I think to myself "Ok now I go into a left foot forward grind". I immediately widen my stance and prepare to slide left foot forward.
4th. I scissor the rail to stop my leftward momentum.
thanks for the help, I actually did some slides unatural before this and got them down, however when I looked back at the video, my feet were pretty close together so I imagine that is probably why I slipped out