No longer twins...

Today I went to OBGYN after successful IVF treatment and found out that one of my twins' heart was no longer moving😭 It was a big shock for us but I'm telling myself I have to be strong for the other one. I'm 9 weeks+2 days today and hoping the pregnancy will last... Has anyone had a similar experience? I'm feeling down but I guess I should still be happy to have one. It's been an emotional roller coaster all day.