On a thin line

Idk what to do. I miss him so much and being pregnant doesn't help? What can I do to get over my boyfriend leaving me and not being here for my pregnancy at all? I wish he could please come back into my life and he just doesn't. He didn't care about my birthday only appointment he went to was the first one and they couldn't even see the baby. I just didn't expect four years of us being together to just end this badly. I didn't know waking up everyday not next to him could hurt so bad. I need a way to get over it and nothing works. Should I get therapy? Take meds once I am done breast feeding cause this will hurt for a lifetime. Any advice? Him not being here makes my pregnancy less and less enjoyable. And I feel so sorry for my baby. Cause I thought me and him would have been a team. Why does it hurt so much? If he decides to come back in my life I mean if it be just for the baby or for both of us should I let him? I am so lost.