Y did my girl chang her number and did not tell me or call me to give me the new one i am up set and crying?

we were happy 3 days a go and she went to get her hair dun on sunday she Sed she would call me wen she was dun but she never did call me i called for 5 days in a row and got no anser or call back on the 6 day she chang her number i cant stop crying i love her so much wut do i do plz help me plz she is all i have