"It's definitely a combination of excitement and nerves, because my breathing isn't exactly the same," the singer, 34, tells PEOPLE. "I'm feeling out my breathing through my nose trying to see if the swelling's going down. The sensation is mildly different, so that makes me fearful about singing."
DeGraw says the Aug. 8 attack by unknown assailants left him completely unrecognizable.
"When I first saw my face, it looked like evil me. I had some fractures in my cheekbone and eye and nose. Everything was completely swollen," he says.
Two weeks later: "I have a little mark on my nose from stitches. If you saw me right now, you'd think I'd cut myself shaving on my nose. It literally looks like there's almost nothing visibly wrong anymore," he says.
And although his physical appearance is returning to normal, DeGraw suffered a severe concussion, which he says has altered his memory and left him disoriented.
"My brain definitely got sloshed around in my skull during that walk home [afterwards]," he says. "I still get dizzy – particularly if I stand up from sitting down."
Remembering That NightAs for what he remembers of the incident, "I had a night off, and I met up with some friends at the bar I own with my brother. We had a few drinks. I put my friends in a cab and I walked home because I live pretty close. I remember maybe three guys said something to me and I didn't appreciate it, and I guess I let them know I didn't appreciate it. They weren't exactly on the debate team, so I ended up with a tube down my throat," he says.
"I just literally remember an exchange of words that lasted a second and then being very bloody."
Was he drunk? "I can't say I was drunk. I know I had a few drinks with friends."
DeGraw says the police are still piecing details together, but he understands they have bigger priorities. "There are many and much worse crimes happening than me getting beat up," he tells PEOPLE. "I don't think that it's necessarily even fair that I got the attention I did."
The singer – who will release his fourth album, Sweeter, on Sept. 20 – says he's moving on – and continuing to heal.
"I'm not living in fear," he says. "It was a terrible night for me, but fortunately I got through it. I still look like my mother, and onward and upward."