Hi Alison - sorry you are feeling so low, Ive been through it too many years ago but we got back together in the end and are very happy. Has he given you any explaination? Does he just want some time to himself?
If there is no chance of a reconcilliation you will have to take each day as it comes and try to plan things to do at weekends when it is worse, If you have lots of friends turn to them and arrange nights/days out- anything to take your mind off him. I know it wont feel the same but eventually you may start enjoying things again. Thinking of you. x