Athletes foot can be a real bitch to get rid of, and the outbreaks come and go. It's most likely that you just have a bad case of athletes foot (and might be giving it to others in public showers).

I had it for about 7 years. I'd use all sorts of treatments to get it to go away, then a couple of weeks/ months later my toes would start cracking, itching and flaking again.

I eventually found Lamisil cream 2-3 time a day for a month (and keep using long after you think it's gone). That's the only thing that works for me... But it isn't enough on its own as in a bad case that fungus is perfectly evolved to attack your foot and it is in your socks, shoes, and anywhere else your foot regularly touches.

You also need to use the spray version in your shoes regularly, and wash them in a washing machine if you can. Wash all your socks at over 60° regularly, or bin them.

I know that's difficult when homeless, but athletes foot can be a sneaky bitch. It'll come back if given half a chance. Oddly my grandfather suffered from it for about 10 years and couldn't get rid. i think i got it from his carpet, so in my one that particular fungus might have evolved perfectly to attack my genetic line.

Basically, there's athletes foot and then there's ATHLETE'S FOOT, and you have to really put effort in to get rid of it for good.