Boob reduction

I'm 21 years old ,115 pound  and my height it's 4''11 , my job requires a lot of lifting and my bad it's starting to hurt a lot and I think my boobs play a big part of it since I'm 
36 Dd idk if I should ta boob reduction or see if they get smaller by going tithe gym since I'm gonna start going to the gym now please help :(