Sorry to say, but yeah, it looks like an abscess & this is a typical way that snakes get them, & yes, on their face/nose area. DO see a vet, but also you need to make
sure it doesn't keep happening. You may know that in snakes, pus that forms is mostly solid & does NOT drain without medical help (from your vet). It's not too bad
yet...these can get far worse & jeopardize your snake's life, because this infection is on their head (hint, near the brain & vital functions), so it's not to be ignored. I hope
you can figure out how to house him so he does not continue to do this...he has to heal.