Dear sir, i had a girl friend 4 months back, she is dealing with the problem of ocd or ocpd. now she want to leave me, ?

Help her: Help her get help for her ocd. When that is done and she is feeling better, have a talk with her about her feelings.

Take Care of You: Wow. This is a hard one. I am not sure what you think we can offer here. But, here goes. You may need to let her go. She has a journey to complete and probably a lot of work with mental health. You can be patient, you can be forgiving, but, most of all you must be kind to her and to yourself. If you cannot let her go easily please get some therapy.