He's above your fireplace... and it's warm there... do you have fires burning in the fireplace? I would be very concerned that smoke is making the RI worse.

Whether or not you are burning fires in the fireplace, I would strongly suggest getting the snake set up properly (check out the caresheet on this site, or ask for help, but from your limited description, it doesn't sound like proper conditions).

It is also very important to make sure the medicine is working to fight the infections that your snake has. While some medicines are good against most RIs, the only way to be sure is to have a culture taken, find out what bacteria are infecting your snake, and get a medicine that is effective against those specific strains of bacteria. Please get this done right away.

Although I am not a vet, and I don't think even the world's best herp vet could give you a definitive answer based on your limited description, my guess would be that your snake is not so far deformed that he'll have any troubles IF you get the infections cleared up quickly. The lower jaw not looking right may be simply a result of the discomfort the snake is in, causing it to not hold its mouth in the proper position, rather than any permanent deformity.