Tea tree oil or Nonyx Nail Gel have both worked for me in the past. You must be patient and diligent to do it every day until it's all gone…typically 6+ months. Keep in mind that nail fungus takes a L O O O N G time to get rid of, especially toe nails, as they grow at a slower rate than finger nails. Other items to consider, make sure to fully dry your feet after showering, prior to putting on socks/shoes and change your socks regularly.
Depending on your medical insurance, it's worth doing it properly by having your doctor send out for a culture growth to identify the strain (takes 2-5 weeks for a lab to grow a fungus/bacteria culture from your nail clippings). You're doctor can then properly diagnose and treat it through oral Rx medication. I hope this helps.