Wow...I'm sorry...
Please be sure to get the other wing clipped immediately, as it's far more dangerous for him to only have one wing clipped that way than both, as with only one wing clipped he's totally out of balance...
Unfortunately it's going to take at least a year for his wings to grow back in to the point where he can even glide again, so yes, it's going to be very important that you move his cage to a low place, like the floor, and not let him climb anywhere up high, because if he falls or if he tries to fly off of something, he's going to cause himself great harm.
****For future reference, if you ever clip him again (there's nothing wrong with clipping your bird's wings, but he still must be able to glide a good distance for his safety) make sure that you Verbally request that the they only clip the outermost 3-4 Primary Flight Feathers and that's IT.
***Do not EVER take your bird back to that Vet for anything!!!! I'm going to assume that this Vet was an "Exotic's" Vet, or just a General dog/cat vet, neither which have any business clipping a bird if they have no experience doing so...However, imagine if you had taken Loki to this Vet because he was sick or injured! Imagine what this Vet might have done, or NOT done!
You need to find either a Certified Avian Vet, or an Avian Specialist Vet, obviously it's worth driving a few hours one-way when your bird needs it. Never take him back to an "Exotic" Vet or a General Vet because this is exactly what can happen...
****As far as the Vet who did this, you absolutely need to report them to your State Veterinary Board, they are the ones who can prevent this Vet from hurting another bird, otherwise they will just keep doing the same thing to more birds! Take a photo of Loki right now, the way this Vet left him, and then scan or take a photo of the receipt or medical statement that you got from this Vet as proof that they are the one who did this to him and then Google for your State Veterinary Board. They will have a link on their website to file complaints, and that's where you need to write an email to them explaining what this Vet did to you bird, how detrimental it is to him, and then embed the photo of Loki and the receipt from this Vet into your email, or attach them as files and send them to the Board! This is extremely important for you to do, because this Vet needs to be EDUCATED about this immediately...They will listen to the State Veterinary Licensing Board, if they don't they will lose their license...