Hi Simon, welcome to the forums.

I'm sorry to hear about your girlfriend. It is extremely difficult to lose someone you love. I agree with smmath though as well - cutting is only a temporary fix. In the long-term it often makes things worse. Have you been able to talk to someone about what you are feeling and have been through? Professionals can usually help you with other methods to manage those feelings so that you don't need to rely on cutting to get through.