Can I make a treatment to cure nail infections/fungi?

Yes. You can try tea tree oil, vick's vapo rub or duct tape. These are easy to buy over the counter.
Nail fungus. Very difficult to treat with otc preparations. Soem have founds success with tea tree oil, some with vick's vapor rub. Try Lamisil (terbinafine) cream twice a day for 3 months. If there is no improvement, see your doctor.