Your workout routine changes, your done working out your chest, sorry, thats supposed to be flab now. it will turn into mush pretty quick after a month or two on hrt.
All strength training now goes to your hips and butt. Theres tons ofyoutube videos for specific workouts for these areas, check em out. Use heavy weights, adding more muscle here will help balance your lower body with your larger upper body. Keep the cardio up for sure.
I'm still dooing abs, i cannot stand any flab on my stomach, so if having masculine ab's forever is my destiny, so be it. Girls workout abs too tho.
Hormones and time will also help.
Main point is, dont strength train your upper body at ALL.