Chopin sonata no.2

[punter]

I'm having a bit of trouble with the 1st movement, in the opening agitato section, I can play it well, except i want it a bit faster, and when i try going faster it gets messy.  Are there any specific things i could try or should i just do more slow practice? 

Also in the energico section (bars 137-152), I can play hs perfectly at the speed i want, but when i put them together at full speed it falls apart.  I've tried starting slowly and working up speed, but as soon as i start getting fast again it collapses.  any hints?

Thanks,
Punter