It sounds more like Postprandial Hypotension, when there's an excessive decrease in blood pressure after a meal. Symptoms can be feeling dizzy and light-headed, fainting, or falling. A doctor can measure blood pressure before and after a meal in order to make a diagnosis.
Oh, and about the candida - try to eat plenty of yogurt. Yogurt contains active cultures (bacteria) which feed on yeast and will help keep the balance in your intestines. But obviously you can't just eat yogurt all the time, if your underlying problem is more tenacious. Your doctor could prescribe an anti-fungal like diflucan (generic name fluconazole), typically used to treat vaginal yeast infections, but it would work in your intestines too, probably.
If you had liver problems there would be signs of jaundice - yellowed whites of the eyes, yellow skin & fingernails, et cetera. I doubt you have a toxic liver - you would probably be in the hospital now if that was your problem.
FYI, I'm not a doctor, just some ideas... First I would recommend posting this under endocrinology, you're probably more likely to get the answer you are looking for there.
Excessive candida can be the result of frequently high blood sugar. Since your symptoms seem to be responding to food, i.e. an increase in blood sugar after eating, it could be insulin resistance. Many doctors might say that you're too young to develop type II diabetes, but being overweight (or inactive) does put you at an increased risk. There could also be a different endocrine problem having an affect on insulin, such as polycystic ovarian syndrome (do you have irregular periods, excess hair growth?), which has been linked to type II diabetes and overweight women. Excess cortisol could also raise blood sugar, but those conditions are more rare. But it sounds like diabetes. Keep an eye out for chronic thirst and urination, but even without those symptoms, it could be possible.
Another idea is that perhaps you have the opposite problem. Usually, when you eat your blood sugar initially increases, then insulin is released to bring blood sugar back to normal. It is possible that your insulin is overacting, causing your blood sugar to fall below normal and making you pass out. Either way, I would get your blood glucose checked by a doctor.