Getting over dad not wanting to be apart of it

How do I get over my sons dad not wanting to be in his child’s life? I feel like I have to threaten him or force him to be in his life. I’m tired. I’m only 17 weeks. I feel like I failed my baby ☹️. I cry everyday & apologize to my son. I gave my first bby a great dad! But not this one. Any advice. Feel like a huge piece of shit. He made me choose between him or the baby then told me to keep him and his family out of it. 😢