Burning pain in feet whilst running. Advice needed PLEASE!!!

[rac1984]

I've recently started running but am being crippled by burning pain and/or numbness in the balls of my feet.
I went to a proper running shop to be fitted properly for my trainers (now using new balance ones with extra cushioned training socks).
This is my 3rd week of training and not running far at the minute compared to most. My uncle is well trained in long distance running and so is helping me do it properly but after 3 weeks my feet are beginning to hurt again. Just got back from my run and need help please guys.
Not exactly healthy and rather overweight if honest but I 'm really wanting to do it this time, i'm just concerned its going to put me off like previous times when i've ended up limping home!
Any anvice or further questions will be gratefully recieved!! Many thanks...