I dont want to lose her...?

Due to unavoidable cirstances for now i am in a long distance relationship with my woman. Of late i have noticed that she's become really snappy. So i asked her what the problem was. She burst into tears and told me that she misses me alot and wanted me to ring her more often. I have to admit that i rarely ring her because am busy and sometimes am broke. I send her lots of emails. But she always rings me and we talk 4 long hours. I am always happy to hear from her. So she said just the same way i feel good when she rings me, she wants to feel like that too. She wants me to ring her and take time to talk to her etc. She just didnt want to be the only one saving her little money to contact me by phone. I love her so much because she's been there for me even when i didnt have any finances. At some point she even isted me with my rent after working so hard etc. And she's been there for me emotionally as well. I want to marry her once am sorted. She's a great woman. How can i keep her happy in the meantime?? I started to ring her daily as she indicated and i have to say i have seen a great change in her. She is back to her happy polite self. I would appreciate any feedback.