Eh - she's never been able to show you any affection?? It's sad you didn't realise maybe she's not the one for you before you had kids. Best hope now is proper counciling (eg Relate) and if that fails you need to decide if you can handle sticking with a bad relationship purely for you kids, or you need to end it and move on.
You misunderstand me, sorry, She can't show affection when she doesn't feel it, when she is really angry at me for something ive done or not done!