How do I go about trying more foods?

I’ve only been eating a couple pieces of meat everyday for a couple months and a vegan nutricional shake w no allergens..and I feel like death is around the corner. I’m so weak and tired all the time. I have no idea what supplements I should be taking and how to go about trying new foods… I’m taking cromolyn sodium and so far 2 xylas a day and famodine at night that I sometimes forget to take..I’m really scared..