Hang in there, Laureanne!
I had a similar tongue graft, but the tissue is from my left thigh. I had a PEG tube in until a week after radiation, but never used it after I could swallow, which was about a month after my surgery. I also had a trach, which came out about 3 weeks post surgery. I am a fast healer and was helped by a lot of prayers, but like you, wanted to know, "how long?" It is obviously different for everyone, but I was diligent to get healthy as soon as possible. It has been 7 months since my surgery, and my speech continues to get better. Some days, it seems, my tongue is more swollen than others, and also depends on whether or not I tried to eat some food that is more textured, like nuts or granola. Someone said to recored your speech, so that over time, you can hear the improvement. I wish I had done that because I am often hard on myself for not speaking more articulately. I know I have come far, but would like to hear it for myself.

Hang in there, and before you know it, some things will start to seem "normal."