Mono is different for everyone. When I had it I had strep throat like symptoms, bronchitis symptoms, etc. And kept getting diagnoses with lots of different things before I go tested for mono. My friend on the other hand had it about 6 months ago and while she tested positive she just felt like she had a bad cold. The duration also varies from person to person but you can expect have it for a month to two months on average.
If you are having trouble with your throat and eating, try eating only super soft foods. I had my tonsils out last year and found the easiest foods to eat were mashed potatoes, applesauce, grits, jello, ice cream, etc. Just stick to foods like that until you start to feel better and can handle swallowing other foods.