Even if it seems difficult to impossible, try and eat 4 to 6 meals a day. Try not to eat 1 hour before and after your workouts. Make sure you drink a lot of water. Water is very underestimated... Think of your body as a car engine. Imagine all the pipes and wires transporting electricity and fuel to the combustion chamer. The freer and cleaner the pipes and wires are the better your motor will run. If you don't drink a minimum of 2 liters each day in a period of 12 to 14 hours (coz that's when you are awake and active!) your blood will be thick and your heart will struggle to transport all the oxgyen and nutrients throughout your body. Think of dirty, sticky black oils in your engine... That oil will break down your engine and make it slower and less responsive. Especially after you took it for an intensive ride up the hills... Same with you, when you work out and you don't have enough nutrition and water in your system you will get tired and grumpy and demotivated... To kick start the process, why don't you try a dairy and meat free foods for 3 weeks. This will force you to avoid processed foods and most importantly allow your body to absorb vital nutrients without any efforts. Just as if by magic you will feel already much fitter after day 4. Just imagine the feeling of not being bloated, tired, dry mouth, supple joints, bright eyes and a really really nice skin - and that already after day 4 :) to start off you can eat avocados, tomatoes, cucumbers, potatoes, rice, (fresh corn) all sorts of green leaves, lemons, ginger, apples, bananas, grapes ( all fruits and veggies really) I hope you can do something with this info... I have been able (thank god) to help quite a lot of people to change their lives and become healthier and happier. I hope you can build further on this info and let me know how you feel in 3 weeks time :))
It might be the food you are eating before and after workouts. I would maybe consult another doctor and see what they think. Hope you feel better soon.