Single mom and pregnant

So I just found out I'm pregnant, just over 8 weeks. I conceived this baby, my second, 2 or 3 days before my boyfriend tried to commit suicide. He didn't succeed but he did disappear and I haven't heard from him since the end of january. I'm terrified to tell him because he's unstable and also I have no idea where he is or how to find him. Do I tell him? Do i try and recieve support from him? I'm terrified he won't want to be around and I don't want him in and out of this baby's life. My daughter's dad is great and I'm very lucky to have him as her father. And we get along great! So I would be heartbroken if this other guy doesn't want to be in my second child's life. Advice please!!