My girlfriend wants a break from our relationship due to her mom's death,why is she so cold towards me?

My girlfriend and I have had a nice healthy long-distance relationship for about 3 years. We see each other once per month and are happy together. Two months ago my girlfriend's mom died of multiple sclerosis (she was diagnosed 3-4 years ago). When she first knew about her mom's death, she was pretty confused and couldn't face it, but she was still affectionate towards me and wanted my support .2 weeks later she went back home to france. Once there, she called me 3 days later and wanted a break from our relationship. I had no choice but to accept. Right now we have been on this break for a little more than a month, and she is calling me less and less . Everytime I speak to her, I stress how much I love her and how much I want to see her. She constantly answers that she needs time for herself and that she can't show me the affection I expect from her. I love her so much and I have the impression that I am losing her slowly. I dont know what to do anymore to save this relationship