Unfortunately, I had mohs surgery three days ago on my left cheek.
Thereafter, a plastic surgeon did a flap to close it.
A scar will undoubtedly remain.
How does one gain their "self confidence" back with this situation?
Also, is there a make up type covering for this?
Thank you.

Plastic surgeons pretty much do nothing but making sure you don't have scars.
There's no reason to lose your self confidence in the first place. You just had important surgery. If you feel a need to say something, you say "I just had surgery on a skin cancer."
NO ONE is going to cringe or even care. You said last month it was small!
No, don't cover it with make up. You need air to heal skin and not clog pores. Soap and water only.
I just got my results back the other day, on a basal cell on my forearm, a pink one a little smaller than a dime.
I don't know anyone besides me who thought a pink one could be cancerous, but it can.

A friend had mohs surgery last year, part of her nose was removed, she met a man who fell in love with her (not her nose), and now they are happily married and raising dogs.

You are still you, not a cheek. Let it heal, and then go from there with possibly a dermatologist or cosmetic surgeon advising you.

"A scar will undoubtedly remain". After only 3 days there is no way to tell. I had MOHS on my back and after 5 months you cannot see a thing.