Firstly, it appears that you might have allergies caused by the petroleum fumes. Why don't you ask your supervisor to help you. Say maybe you can change your position from pumping gasoline to cashier or work nigh shifts when it wont be very busy.
Secondly, you need to force yourself to eat at least 3 times a day and few snacks in between. Anything high in fibers, vitamin D, zinc, selenium, Calcium, magnesium, would help clear out the xenoestrogens from petroleum fumes.
Drink whole milk, eat oats, porridge with milk and cinnamon, potatoes (wash them, throw them in a pot, sprinkle them with oil, some paprika poweder -hot or sweet, - lemon juice and cook them in the oven at medium heat until they are cooked they could be eaten hot or cold); broccoli, celery, beans are high in fibers, snack on nuts, any nuts, raisins, they are high in carbs, chocolate, if you like eat turmeric and curry foods, turmeric helps with the male hormone and could help clear out xenoestrogens from petroleum fumes.
I hope this helps. God bless!
It's possible the place you're working is not safe. Petroleum and the chemicals used along with it are highly toxic, and will affect some more than others and will affect some right away and others down the road. It is also highly estrogenic, which might have thrown off your testosterone levels. If the place you're working isn't following very safe procedures, you just might have to find a different line of work, since you say this all started when you started working there.