Nervous For Rainbow

This will be our rainbow baby. And I am having the hardest time keeping even a little bit calm. Every time I feel a little bit fine, I get nervous and start to worry. I can barely enjoy this pregnancy. I'm only 6 weeks 2 days. But I can't be excited while feeling this way. I just can't. We want a baby more than anything. This is our little miracle. But I won't feel completely okay until he or she is in our arms. 
How can I combat this?