Steroids don't mix with a high body fat environment. This especially goes for a harsh steroid like trenbolone. Fat loss should come from diet and exercise only. Honestly, I only recommend steroids for those who have been consistent with their training and a solid bodybuilding diet for several years. There is no easy way out or magic pill for you my friend.
I'm afraid hard work is your only option. Steroids at this point would strain your internal organs and lipids to the max and with all of the fat you are carrying, you will most likely experience gyno (bitch tits). At your age, it would be much harder to recover from the damage so expect some serious problems if you go this route