Deryck Whibley -- Healthy Again After Hitting Rock Bottom

Deryck Whibley and Sum 41 were back together this week for the first time in a while, but the real story is how good he looked ... a year after nearly drinking himself to death.

The band got back together for a performance at the Alternative Press Music Awards in Ohio after taking a break so Whibley, who almost died in 2014 from alcohol abuse, could deal with his issues.

Whibley was actually placed in a coma for a week so his body could detox.

Deryck says he still has trouble walking and is still undergoing extensive physical therapy.

Seems like it's working.