Always worried

I'm 11.5 weeks with twins, and of course I do research all the time about twin pregnancy. I've become so worried that one or both babies won't develop or make it that I can't enjoy being pregnant with two blessings. I try very hard not to stress or not to think about it but I fear I won't be able to relax until   I have both babies in my arms. Is anyone else worried all day every day? I read all these posts that just break my heart and I can't help but to be scared.