Whether or not candida is the “main” issue, you can be sure you have dysbiosis of some kind. All that sugar and starch needs to be cut out right away because it feeds all the wrong bugs that are likely dominant since the antibiotic use. The abundance of wheat, potatoes and other starches, sugar/fructose, vegetable oils etc is why I don’t buy into the whole vegan/vegetarian diets are healthy thing.
It can be hard to establish whether or not you have a candida overgrowth without obvious signs like thrush or extensive testing. Following the protocol here and restoring your gut flora, while taking precautions against yeast, should do a lot to help regardless. Antibiotics and unbalanced diet destroy gut ecology, and alleviating symptoms means doing everything you can to reverse this process.