How do I get over the only man I’ve ever loved.

I’ve been with my husband from I was 14, I’m 35 this year. I’ve 3 beautiful girls with him and I’m 21+3 weeks pregnant. We where only meant to take a time out for me to get my head straight. I suffer with depression. I had heard he was seeing someone else. So needed a bit of space. It had happened before. He was calling everyday telling me he loved me, that we’d get through it. That it was all lies. Then at Christmas he said that yes he’d slept with her once and that was it. But we could still be together. My head was a mess I said I still needed time to think about everything. Then when I thought things where going good I told him to come back home, he said no he’d stay where he was to make sure it was really what I wanted. Then I found out I was pregnant and the shit hit the fan. He said it’s not his. 3 weeks after telling him I’m pregnant he tells me that he’s living with the other woman. That he’s been seeing her the whole time. I still love him and feel like a complete fool. I just feel very alone.