I had horrible diastasis with my 1st large baby (and I'm 7 months again so it's getting worse). I recently got Julie Tupler's Lose Your Mummy Tummy book which is not a diet book as the name suggests, but a diastasis recti rehab book. It was recommended to me by a friend who had it so severe that she needed surgical correction after her first few kids but used Tupler's technique successfully to avoid severe diastasis with her 4th. It explains a lot about the numerous mistakes women make when they get it (ie crunches) and how to correct it.
Sorry, no advice for leaking, I never had it!
Start: 145lbs around December 2012(*Baby born November 2012)
Mini-goal 1: 140lbs*Achieved January 20th, 2013
Mini-goal 2: 135lbs*Achieved February 18th, 2013
Mini-goal 3: 130lbs*Achieved April 8, 2013
Mini-goal 4: 125lbs
Long-term goal: 120-125lbs
Losing while nursing... slow and steady
Maintainer 2004-2009 & 2 babies & now losing from Nov 2012 - present