I haven't had sex with my girlfriend for 4 months been together for over 3 years, she goes out during the week with work mates well at least I think that's what she's doing but she doesn't have anough time to be cheating on me! And lately she doesn't like me touching her and if I ask her about it she gets really angry about it but she hasn't got a explanation for what's going on she doesn't no,our sex life was great! But now I don't no were to turn help!!

No one can help you here I'm afraid, there are many reasons she may have gone off sex, stress, overworked, feeling under appreciated,she may not find you attractive anymore or feels unattractive herself. You need to communicate. It may be hard to get her to open up but you have to try if you want things to work out otherwise you have two options stay in a sexless relationship or get out.

What has changed in other areas of this relationship?

Sounds like you guys need to talk..