First of all don't go to the doctor again unless it's a LIFE OR DEATH situation, even if it is that serious always research natural ways of treating yourself before turning to conventional medicine.
Your problem is leaky gut/indigestion.
What you will need is some coconut oil, organic lemons, Penta water and that's all you will be using for a week. Upon awaking squeeze half a lemon into 2 bottles of Penta water and drink it, 2 hours later take 2 tablespoons of coconut oil and keep taking the coconut oil every 2 hours, what this does is kill the candida and gives your body a chance to recover because coconut oil is easily digested and supplies you energy without taxing your digestive system, again don't eat or drink anything else. Do this for 4 days and after that you have to watch what you eat, avoid bread, fruit juices(unless freshly squeezed by you). I see that you are trying to gain weight, stock up on whole milk organic kefirs/yogurts and red meats.
Meats are hard to digest so you will need to take a tablespoon of undiluted Bragg's ACV before every meat meal. After a few weeks if you are feeling better do a 4 day orange fast and see how that works vitamin c depletes copper out of your body so that zinc can be the dominant mineral, I think that you are trying to gain muscle weight, 2 raw egg yolks with the membranes after workouts should take care of the zinc.