How can i drop the weight?

alright i used to weigh between 230 - 250 lbs at 6' when i was 18-21 playing college football i was built like a brick shithouse to give you an idea i was at one point 6 foot tall 240 lbs with only 6% body fat i was solid muscle (you can use your imagination how i got that muscular at that age) but ever since quiting football due to partying i.e drinking too much beer and using drugs (at that time) ive gained nearly 80 lbs of fat blubber i got a desk job where i sit and do nothing all day starting putting on pounds not eating right and at the right times. i used to have a personal trainer i know how to loose weight, burn more calories that you take in in a day. eat small meals throughout the day. and exercise as much as possible without overexercising of course. but i wanna know a way to not only burn more calories and exercise but i wanna know if there are supplements i should be taking or any advice as to what i should do to speed up the process