Feet Injury/Inflammation

I was recently ‘‘forced’’ to take a high pay, little stress job, but where i am 11 hours a day on my feet, for the next six months.
Soon i was starting to get unbearable pain in my feet. First i thought it was some kind of athletes foot infection that was causing the pain, but after using some anti-fungal creams on my own with no result i went and saw an doctor. He told me that its not bacterial, and just gave me pain killers, and told me to get better shoes and get used to it. (which i am going to, soon).
But until then, i need help, since the pain killers are not helping me at all, and i still need to work, and workout.
I researched a little bit on my own, and the only thing i found was this plantar fasciitis. But i dont think that i have that, since there is no physical signs of anything. Only this overwhelming pain that i feel, shows that i have any condition at all.

Anyways, i wanted to ask you if anybody had a similar problem, and what would help? I am already taking fish oil and the occasional ibuprofen, but nothing. Also, in your opinion, what should i look out for when i go and buy shoes for such a job?