The hours you've got are valid forever - the CAA can't take those away from you. You'll certainly find yourself re sitting all the ground school exams for the PPL, as you lose your credits after a couple of years if you haven't applied for the licence. You'll be surprised how quickly it comes back to you, I'd say rip in there and get yourself solo in the circuit again to get the confidence level back up, do a couple of revision flights on forced landings etc and then try and move into the cross country flying fairly quickly.
Unless you've already got your 150 NM qualifying XC certificate you'll need to do it before the PPL issue, and your instructor will no doubt wish to spend a few hours in the aircraft with you before he/she goes and sends you off on a big cross country on your own. Once you've got that XC flying wrapped up, and re sat the theory exams, then you can get into the serious business of revising and practicing for the flight test.
Any school that reckons you should 'just use the hours that you've got as credit for CPL' is talking out a big hole in their bottom, because you can't sit a CPL flight test - or even enrol in a CPL ground school theory course for that matter - without already having had a PPL issued.