Husband cheated with sister!

Hannah
It's been over a week since I found out my husband started cheating on me with my sister before we got married. She is/was my best friend, and my husband and I are high school sweethearts. She even moved to Seattle from Missouri to live with us. Well she finally came clean, and bam life is devastating. We have a 2 1/2 year old and I am currently almost 7 months pregnant with our second boy. We've always said we would try to work it out if something like this happened, to keep the family together. We are starting marriage counseling on Monday, but I am utterly and completely heartbroken. 💔