How long does it take until heartache goes away?

Right now I'm trying to have a civil conversation with my babys father, and he never answers the phone for me he only texts me. He is supposed to be giving me some money to pay for something, and I'm trying to call him to see when we'll meet up and stuff but he ignores me. he texted me saying that if it's not about the baby then he doesn't have to talk to me. but even if it's about the baby it's hard to talk to him and get in contact with him, the only way I can get in contact with him is by text. I'm just crying so hard right now cuz i feel so alone and so hurt, so.....low. how long will the heatache last? and how can i get over this i feel so horrible