Thrush or oral yeast, is an IMbalance, and can be caused by all of those oral antibiotics you are taking, have been taking, and it can be progressive once the body is out of whack. We all have good or beneficial bacteria in our systems. We all have bad bacteria in our systems. All the time! If you do something to throw it out of balance, it can take a long time to rebalance it. Oral ANTI biotics or (against life) can kill ALL bacteria in your mouth, gut and sometime skin. it doesnt care if a bacteria is good, bad, or helpful, all bacteria that is affected by that strain of drug must die. If you stay on it long enough, or keep having repeated doses or antibiotics you dont give your body a chance to play catch up. Most of the time when we stop taking the pills our bodies go back to good housekeeping. Some times we find that the good bacteria were so overwhelmed and removed, that we are suseptable to the bad over growing first. That is what happens in thrush, or oral/vaginal candida. What would really help is to REbalance your system. Add back in the good stuff, to help your body rebalance.
Yogurts with LIVE cultures (read the lable) will help do that. Yes, its ok to add fruit to it. Curbing the sugars will help, but unless you start adding back in some good stuff, its an uphill fight. PRO biotics (FOR life) are a good thing. IF you are unwilling/unable to eat yogurt (GAWD, I hate the taste) there are pills. Acidophollus, Lactobacillis, and the like. Try to pick a better brand. keep them in the fridge. This will help keep the good bacteria alive. As you start to replenish the good stuff, you will notice that the thrush will really back off. leave it on your tongue for an extra minute, and swirl it around your mouth. The good bacteria will help soothe and heal.
After you have this thing back in balance, you can readd your sugar full gums, candies, and treats, but since you have had this once, you should be aware of it each time you take any antibiotic.
I hope you are feeling better soon. I had that and its just awful.