Vauxhall Corsa diesel 1.5 problems

Hi there, I have a vauxhall corsa diesel 1.5 N reg (1996 I think), ive only had it 3 months but am having problems with it, when I first bought it the guy told me that it wasnt too good on cold mornings. It still started first time but took a slightly longer turn on the key. This wasnt a problem. But today I went to start it after leaving it standing for 9 hours or so, and it really didnt want to start up, took me 3 long attempts to get it goin, and once it did get goin it was juddering very bad (when stood still) as though it was about to cut out. I have also noticed that white smoke has been coming out of the exhaust when I start it after its been stood for longer then 8 hours or so (after 5 seconds or so this smoke is gone), this has a funny smell with it which I can only describe as burning pan handles or burning rubber. Hope ive given as much info as possible. Thanks in advance