My hands and toes change colour and my fingers feel stiff and always feeling sick and dizzy and tired but up most of the night awake?

Raynaud's: You may have raynaud's syndrome, which involves constriction of the small capillaries in your fingers and toes. The other symptoms may be part of a bigger issue, so you should see your primary care physician for further evaluation. Good luck!

Many reasons: There are many reasons for this. If you are a smoker-- could cause this. Reaction to cold could cause this and many other diseases like diabetes etc. You must consult your physician or podiatrist for a much more in-depth work up.