WWE Star Big Daddy V -- Dramatic Weight Loss Before Deadly Heart Attack

Ex-WWE superstar Big Daddy V was on the road to getting healthy -- losing about 100 lbs. -- which is why his death by a heart attack this week shocked everyone who knew him ... according to his wife.

Cassandra Frazier tells TMZ ... V started getting healthy last year after doctors said his blood pressure was way too high, and it was affecting his diabetes.

She says the wrestler reacted by removing most salt and sugar from his diet ... losing most of the weight in the last 6 months -- and doctors said his blood pressure dropped to a healthy level.

Obviously, the weight loss came too late ... or it was too much too quickly.

B.D.V. died from a major heart attack Tuesday night.

Cassandra says, "I guess the Good Lord wanted him... I wanted him too, but He won."