Nutritional help needed!!

Hi, I'm looking for some nutritional advice. I'd like to go back to being a vegan as I'm dairy intolerant, but since I was last a vegan, I have been diagnosed with ibs and can no longer eat citrus or apples or acidic fruit or juices. My ibs means I can't eat fish or have soya products and meat is beginning to make my ibs flare (hence wanting to be vegan again). I am allergic to some nuts, eggs & kiwi. Is it even possible for me to maintain a healthy diet? I really have no idea what to do.