Some additional protein during molting can be helpful, you can buy commercially prepared egg food for birds or you can offer some hard boiled egg. As for flying he is just going to have to wait until the new feathers grow in. Birds usually molt symmetrically so don't be surprised if the same feathers on the other wing fall out as well.
my oldest, (10+!) has been molting asymmetrically for the last few years. The feathers always grow back normally. I just make sure he has easy access through his cage with ladders and such. If everything else is normal I wouldnt worry!