Pregnant and alone

Currently 16 weeks pregnant with my first and recently found out my husband has a secret girlfriend after being together for 10 years. He has moved out and decided he would rather be with her and work things out with me. Not only am I heartbroken, but also distraught that I have to go through pregnancy alone. Any thoughts about not to be consumed with sadness? How to get through the rough nights? How not to text him begging him to come back? I‘m having a hard time eating and sleeping. I wanted this to be the happiest time of my life and now it’s the worst.