Girlfriend not returning money given in times of need

I have been knowing this girl for the past 3 years now and we have shared a cordial relationship with each other with more of an attachment from my end and she was okay with it. She was financially not sound enough so I wanted to be there for her s d even she wanted me to help so I have helped her when situations demanded . Now she has a problem with me and wants to move ahead and I want my things back and all that I have paid for her because of the mental torture that I had to face from her. She is not willing to give me back my things and the said money and in return she had also served me a personal legal notice from some advocate on harassment. I have enough proof to show that I have done a lot for her but she is refusing to accept this. Kindly help me out. It was a part of my income and now I see that I have been exploited and being accused wrongly. That is giving me a mental pressure .