Need help for a specific thing

Hello, I am new to this stoic way. I (20) had a break up with my gf (18) after 3 years of relationship for about 1 month I was in an emotional crisis then i decide to change it. Started to read Meditations then read Epictetus and now i am reading books of Seneca. İ red 5 books in 1 month and i am confused about something. All this break up happened because of her emotional instability. After month later she called me because she wanted her books that i kept in my place and wanted to give me my stuff back. We talked a bit and the reason of break up is that i make her unhappy all the time. İ was halfway reading meditations and even in that time i learned that happiness comes from ourself no body "makes" us unhappy we just choose to be. After this talking i decide to block her from wp. (My family is against her after that break up btw). And now she sometimes calls me from another phone. Her mum even called me, it was to late for me to pick up so her mum masseged me about that she needs to talked me. İ just keep being careless to her calls but this makes me sometimes think like I am doing something wrong. I think that being careless is not a good thing when i learn that she wants or need whatever to talk to me. I dont know what to do. She being emotionaly unstable is not a thing i can change at the same time my family does not want her anymore and does not want me to talk to her. İs it a virtuous thing to be careless to her calls or am I doing a bad thing not picking her phones up ?