Supertraining

I came to the supertraining group through the United States Olympic  
Weightlifting Team website. 
 
I wanted to join because I am a powerlifter in need of advice.  I am 33  year 
old; 5 feet 7 1/2 inches 235 lbs.  Last year I was diagnosed with  diabetes and 
my doctor wants me to go down to 175 lbs.  I'd like to learn  how to be fit 
and healthy but still be strong in my powerlifting efforts at  175 lbs.  I have 
a hard time balancing cardio, nutrition, and  training.  If I do too much 
cardio my seated behind neck press, bench  press, squat, deadlift go down in 
lbs. 
lifted.  If I don't do any  cardio I can't lose weight according to my 
doctor.  Should I consult a  sports nutritionist?  In my teens and twenties I 
did 
very little cardio;  just the gym workouts forcused on the powerlifts and 
supporting  exercises.  
 
I am just looking for training and nutrition advice. 
 
Thank you.
 
Edwin Freeman, Jr. 
San Francisco