Birds lose feathers all the time, and seeing as this was his own fault, I wouldn't worry too much. If he has a broken feather that's bothering him, he'll pluck it himself, so just let him do his thing. He may be in a little discomfort, but like I said, just let him do his own thing and only handle him if he isn't aggressive about it. If he hasn't plucked the feather after a few days, either it doesn't bother him, or he can't pluck it himself, so watch for any swelling or signs of infection. If you spot anything suspicious looking, you may need to take him to the vet.

While it's cheaper to just sit down with a pair of tweezers and try to pull out the problem feather, it's safer if a vet does it. :)

I have 4 cockatiels and have been through everything, including that. Clip his wings if they are not already clipped, and then just leave the tail alone, as in about 2 months he should be back to normal.

Good luck

What Megan said. If it was a blood feather then blood would be coming out of the feather shaft.

This morning my cockatiel randomly started flying around in his cage when he still had his covers on. I've had him for 2 years and this has never happened. Right now I saw that there are 2 of his tail or wing feathers on the floor medium size and one of his tail feather is falling but is still attached to his body by the tip. What should I do? Should I pluck it out or will he pull it out. Is it a blood feather!? He also hasn't eaten anything yet? Is he in pain?