As to alternative hot drinks - obviously there is a huge range of herbal teas. But have you heard of Barley Cup? It works like coffee - is made from (funilly enough) barley. It may be malted so you may need to check the sugar (maltose) content but it's perfectly pleasant. One warning - it may look like coffe but it tastes very different - a bit of a shock the first time. It also has no caffeine.
If you eat with friends I would hope they would help you if you let them know the situation. Meals where the carbs are separate are easiest. Lunchtime variants could include a really chunky veg soup - more like stew than soup. You can take it to work in a wide-necked flask. I am a bit wierd and I enjoy cold stir-fry so long as it isn't greasy. you could try that.
What about beans as your carb? Not so much baked beans, but red kidney, chickpeas, black-eyed peas that sort of thing. Great hot or cold and provide protein as well. Just a few would make a veggie dish more substantial.