When Darin's weight hit 545 pounds and his heart stopped, he knew he had to change his life.

"545 pounds was something no one should ever experience," he says, explaining that simple things like getting up off a couch, tying his shoes, using a normal chair or walking anywhere lengthy were nearly impossible for him.

Watch: Man’s Jaw-Dropping 570-Pound Weight Loss

When his heart stopped and he awoke to his cat sitting on top of him, he decided to take control of his weight. After losing a mind-blowing 400 pounds, he joins The Doctors to share more about his amazing transformation.

One part of his journey was addressing those who bullied him for his weight by writing them thank you letters. He says that in order to move on with his new life he had to forgive those who wronged him.

Watch: Two Men Go From Obese to Six-Pack Abs

Due to his extreme weight loss, he is now dealing with excess skin. He says that his loose skin not only can cause a smell, but he is also still taunted by strangers about it.

To help Darin with his excess skin, surgeons Dr. Lisa Cassileth, Dr. Kelly Killeen and Dr. Ben Talei offer to remove his excess at no cost to him.

"I just want to tell people, don't give up hope... whatever you're going through in life, there is always going to be someone rooting for you. And if you can't root for yourself, know that I root for you," he adds.

Join #TheDoctors Weight Loss Support Group, a place to interact with a community of people looking to lose weight or maintain their current weight, here!