Renault Trafic. Starts and stalls?

Hello. I have a renault Trafic 2005. I start the engine no problem and as soon as I put my foot on the excelerator it conks out. It has done this for a while and sometimes drives, but is getting worse. Also when I put deisel in it does not show on the dash board fuel gauge. PLEASE can anyone help.
PS I know very little about engines so as much detail as possibe please.