back to diet and i need help

hello all
i do my diet before 8 month
and after 4 month i feel sick
but lose 30 kg from 127 kg to 97 kg .
now i'm 102 kg and 187 cm .
i want complete my diet and work out to be 87 kg .
i decide to do P90x classic .
but i have some question
i will do work out before i sleep how can i eat ?
i only use whey protein and centrum
What is your advice to me ؟
and hope you see my older problem in this post
http://www.myfitnesspal.com/topics/show/1233867-i-loss-30-kg-but-i-have-big-problem