Hi Magen, sorry you had to be here for your dad.
I am not sure how much details you got from your doctor, I have few questions for you:
1. Did your father get a Head Neck CT done? This will tell whether any lymph nodes look suspicious.
2. You mentioned that the cancer is midway between his front and back tongue, is it on left or right side?
3. Did the doctor tell you about the procedure? For tongue they will perform a partial glossectomy. When my dad had, his tongue length was reduced.
4. Depending on whether lymph nodes are affected or not, your father may have selective neck dissection. This may cause issues with neck movement as well as shoulder. It takes a while to recover.
5. Has the doctor planned to fix the tooth as well with the dentist? Should your father receive radiation, dental issues must be resolved before that.
Since things will change a lot and it will take some time to recover from treatment (more should he receive radiation and chemotherapy), please ask him to take good care of himself and eat very well and eat whatever he likes.