Hello, my Husband Kris had his total Glossectomy 3 and a half years ago.
He too is alive and well. It is certainly possible to talk after this surgery. Just try to talk without moving your tongue, for a rough idea of how it will sound. You will need the help of a Speech therapist after the surgery to give you some advice and help. I agree with your surgeon that you may need to tip your head back to aid swallowing. This is how Kris swallows, gravity helps. He stopped using his PEG, about 6 weeks post surgery. He only swallows liquids . I think that this is because he doesn't like the sensation of food coating his oral mouth without being able to clear it up with a tongue. He does swallow all his prescribed pills and our Speech therapist says he should be able to swallow meat!. But he's stubborn and refuses to try.
Kris also had his entire voice box removed during his surgery and he talks. You too will be able to talk. Practice, practice, practice.
Have hope and be positive. You will get through this and life will continue to be great.
Tammy