Hi Jenna,
My wife's case is very similar to yours. She is 33 years old, non-smoker, very healthy ect..dignosed with tongue cancer on her left side of tongue wihch spread into her lymph node on her left side of her neck. She had a partial glosscetomy with free-flap reconstruction, bilateral neck disection, followed by 6 weeks of radiation.
Post surgery she was unable to eat solid food for a few weeks, like you she started drinking carnation and boost, this progessed to fruit and vegtable drinks that we made using a juicer, milk shakes with whey powder(protein)ect... Eventually she was able to eat solid foods like eggs, pasta, fish, beans ect.. this happened around the fourth week., keep in mind that every body is different and heals at differnt rates, please try to be patient and eat/drink what you you can, don't worry so much about your weight, your doctors will tell you if there is anything to worry about, right now just take in as many calories as you can and be happy with that, in the begining my wife was only taking in 1000-1200 calories, not much, but was able to cope, your body will adapt.
Your speech will improve once the swelling subsides and healing takes place.
As for radiation hers started 6 weeks post-surgery as you need some time to heal prior to starting. Radiation is whole different ball game. Its going to be really though, particularly around 2-3 weeks in when the side effects start kicking in and really bad 2-3 weeks following. You will probably only be able to take in liquids during treatment and some time afterwards. Again I'm not trying to scare you, everybody reacts differntly, some better than others. My wife had a severe reaction to radiation but she kept positive with my support and family. She lost alot of weight during radiation treatment, who cares...she took in enogh calories in liquid form to sustain her through this rough time.
On a positive note there is light at the end of the tunnel, about three days ago she started to eat solid foods again pancakes, eggs, fish, ect.. she even had a piece of strawberry cheese cake.
Its been a long and hectic road to this point but we made it here keeping things in perspective. One more thing, please surround youself with support during your treatment, your husband will need to help you get through the rough times.
Good Luck...
johnny