Hello MCR,
I am so sorry to hear of your situation. Cancer is a real roller coaster of emotions. Thank you for reaching out and joining this forum.
I went through a similar surgery (stage 4, half my tongue removed and rebuilt, trache tube to breath, feeding tube, skin grafts, etc) followed by radiation treatment about four years ago. Recovery from surgery went faster than recovery from radiation. I had to learn to judge my radiation recovery in weeks/months rather than days.
One of the best tools for me was keeping a journal. Most of it was a written journal but I took a few videos of my speech too. When i got frustrated, I could go back and see real improvement.
As for learning to speak, drink, and eat again, be patient but persistent. Follow the exercises they give you. I can recall fighting hard to learn to swallow just a few small sips of water again. But, slowly, kept trying, etc and next thing, days/weeks later, it is a little easier. For me, I had to set up a training table (such as 2x/day swallowing exercises, 2x/day tongue exercises, yoga, meditation, faith study, walks, calories, etc). If I hit my targets, I would give myself a treat (favorite movie to watch, brag to my wife, etc.).
Four years out now and I can drink, eat, and speak. People will hear lisp in my speech but they can understand me. I can eat out at restaurants. I use a napkin to cover my mouth if i have to reach in there with a finger to clear something. Everyone recovers at a different rate depending on our surgery, damage from the tumor, treatment, etc.
Stay safe and keep the faith,
Nels