Hello and thanks for trusting me to help you and Oscar today. I'm a veterinarian with over 25 years experience and would be happy to work with you.
Based on the symptoms that you are describing, I would be very concerned that he has developed either a tumor of the brain or spinal tissue. This could explain many of the symptoms you are observing. Of course, tumor would not be the only rule out, but very few things are going to be able to deform that face like that. Tissue inside of the skull can be difficult to visualize, but in his case, due to the deformation you describe, you may be able to get an idea of what may be the cause with xrays. SOme cases, require more advanced imaging, like an MRI, but I would start with an xray to evaluate the skull structures better, including nasal cavity, sinuses
Unfortunately, even if you are able to confirm a mass, it will not let you know the type of tumor unless you are able to obtain a piece of tissue for histopath analysis. Without that information, prognosis and/or possible treatment options cannot be discussed. If the mass is invading sinuses, it may be possible to obtain a sample via a nasal scope. If not anything else, your vet should be able to offer him medications for pain and that may help to improve some of his symptoms.
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.