Should be happy...

I got pregnant in June of this year, it was my first pregnancy, but then I had a miscarriage in August at 11 weeks. I am now 4 weeks pregnant and went to the ob/gyn to confirm and they said everything looks great. I should be super excited because my husband and I really want a baby but I can't seem to shake my anxiousness. Everyone says you should reduce your stress but how do I stop worrying about this? I know I'm doing everything I can, so it's really out of my hands but I feel like I wasn't fully prepared for these feelings after my miscarriage. Does anyone else have this issue and what do you do?