how do i get my health up as someone who doesnt care that much?

i wake up every morning dizzy and extra tired and i cant breathe out of my nose(currently on antibiotics but they arent helping). i only eat once, sometimes zero, times a day. i never have an appetite, and when i do its very little. i have major food sensory issues. if a food is a certain texture i wont eat it. so i dont have a wide variety of food options. im the kind of picky that doesnt even eat chicken tenders at a restaurant. i drink an energy drink every morning at school, followed by a shit ton of water. i always get twitchy and anxious in the afternoon. my mom wont let me go back on my anxiety meds. everytime i walk down stairs it feels like if i go any faster my legs are going to give out. i would ask a doctor but im only 16 and havent been to the doctors in years. 

i dont know how i can feel better