I would not recommend use of cortizone. While it will reduce redness all steroids act to compromise defenses against invading organisms.
I could tell you the treatment, but you really need an in-person evaluation by that undervalued specialist known as the podiatrist. The average M.D. is too concerned with life-threatening illnesses to pay you much attention.
You also have to disinfect the bathroom floor with five percent bleach. Open the windows, hold your breath, and swab it on. Then leave and don't return until the fumes are gone. The buggies hide in the grout.
Instead of a cream, try a powder spray or a liquid spray.. Sometimes cream don't help at all.
I had mine for almost 10 years because of dancing and sports and after using it religiously it went away.
Since you have not had it for very long it should help pretty quick, just go without socks as much as you can, be sure to wash your feet in the shower, and dry your feet really well and don't use the same towel twice as long as you have it.
I used both Lamicil and Tinactin.. if it's dry and cracked open it will sting a little bit, but it soothes the itching/burning too.
Good luck
Wish I saw this sooner...I have it too, try using cortizone to reduce redness and irritation; use Fast actin' tenactin you can buy it at your local pharmacy over the counter....the stuff is for athletes foot and works great!
cheers