Xantia won't start in cold?

Hi there,

I have an N reg Citroen Xantia TD. For a while now I've had to press the accelerator right to the floor while turning the key to get it to fire up but since the cold weather has come in I can rarely get it to start at all, and when it does it chucks out loads of smoke then judders for ages. Is this an easily rectifiable problem?

Any tips would be MUCH appreciated as I can't get to work and I can't afford to have a garage look at it coz every problem I've had in the past cost hundreds of pounds to sort out.

Thanks, Leon