I think i would cut back on the whey protein a little and savie it for your workouts. Get most of your protein from natural foods. Whey stays in your system for about 30 mins. Casein protein says in your system for about 8-9 hours atleast this is info that i read on bodybuilding.com thats why i'm conidering getting some casein to take only before bed time.

I also agree about the potatoes, switch that out with something else. Also if your having trouble eating that much homemade weight gainer shakes may do the trick.

like here:
http://www.bodybuildingforyou.com/ar...in-weight.html