Middle Eastern women (I lived and worked in the Middle East for almost two decades) use yoghurt. But the yoghurt they use is plain, unpasturized and contains the live organism. It's not the sweetened stuff with fruit that you see all the supermarkets. I have heard you can use boric acid, but I have no tried this myself. Look on the internet for home remedies. You will probably find a few. (I wonder if you can use baking soda. See if it is listed. It has a high pH.)
Any medication can cause an allergy. In fact, almost anything can cause an allergy. I find that the most effective antihistamine is still Benadryl. By the way, I have never had success with anti-fungals.
Have you been able to find any alternatives (home remedies, other medications) to any particular fungal medications?
Yeast/fungus need an acid environment, so either you create an environment in which it can't survive, or you use an antiseptic, or an herb or supplement that will kill it. For thrush I used warm salt water several times a day (unfavorable pH for Candida albicans). The thrush was gone and the sores in my mouth healed in three days. (The doctor had prescribed Nystatin, which did absolutely nothing.)
Where is your infection located?
It's a vaginal yeast infection.
I did check up using the plain yogurt and boric acid online and it seems that they do tend to work. I have also read instances in which people have used tea tree oil with similar positive results. I will try the yogurt the next time I get the infection, hopefully it works. Thanks for your help!