Seriously, Belinda's advice is RIGHT! You need to safely expand your menu in order to thrive. Hang in there; baby steps. I once had as limited of a menu/diet as you and literally wasted away.
Do you have a food processor? It's a worthwhile investment. I highly recommend that you buy organic foods only. It makes a huge difference. As Belinda mentioned, getting off prcessed foods is essential. If you do consume poultry/fish, make sure that it is organic/kosher, etc. as Belinda suggested. Vegetables and fruits can be made more digestible/soluable by steaming and pureeing. With soluable fiber, they are safer to consume in small doses to your comfort level. Smoothies are a great suggestion, too. Eat mini-meals and snacks.