Funny i was just thinking about when i was doing brazillian jujistsu today.
Well for me, i took out all cardio and used the mat time as cardio. I would never hit the weights on days that i was training BJJ.
I liked to sip on a shake durring grappling (protein\creatine\carbs). ANd after wards i woudl eat so much damn oats\meat it was stupid lol.
Bro keep it simple and make sure to rest, rest is key.
Good luck onthe fighting.