Check the water for pH, ammonia, and nitrite levels ASAP or the fish could die.  An extremely low pH level or high pH level can cause the fish to dart around .  Very low pH level will kill off the nitrifying bacteria, causing spikes in nitrite and finally ammonia, both of which can be lethal to goldfish and cause the symptoms you are describing.  If the pH is extremely low, bring it up slowly or you will cause the fish to go into pH shock. If the ammonia and nitrite levels are high , perform partial water changes to bring them down immediately.  If the water parameters are just way off, you may have to move the fish to temporary container with new water matched to the same pH as the existing tank to prevent further damages to the fish from the toxins and then slowly adjust the pH back to normal.

I suspect poor tank maintenance as the root cause .If the fish manages to survive you will have to check to see if you are properly cleaning the tank and doing partial  water changes on a regular basis.

He's bumping into things? He's either not comfortable with the water parameters, or he might be bothered by some kind of parasites. It's quite likely to be parasites if his mouth has been hurt so bad from flashing (The rubbing on/bumping into things behavior is called like this) it might develop into mouth rot which it might already have done if you say that his upper lip is getting "cut", since mouth rot causes the lips to come off of the face of the fish if it's not treated in time.

So I think it'd be best if you would first of all test the water and treat against parasites if there's nothing wrong with the water parameters.