Wrapping the cat up will work, but this is a two person job, since cats HATE being restrained and will fight it with all their might.
Did the vet show you how to give a pill? Can the meds be given in liquid form?
Giving the pill must be done smoothly and surely. Any fumbling or panic will not work.
Here is a pictorial on how to do it. Also, I always have a bit of wet cat food on hand, and dab it near the cat's nose when I close the mouth after inserting the pill (as far back in the mouth as you can reach) The cat will lick the food and force it to swallow. Keep the head tilted up and stroke the throat.
Giving cats pills