Cannot sleep, way too nervous/excited!

It's about 6am here, and I'm wide awake went to bed at midnight but having trouble getting back to sleep :( I have my anatomy ultrasound at 20 weeks exactly so in about 4 hours I get to see baby again but I'm scared something is going to be wrong... Everything was fine at the first scan other than an small braxton hicks, anterior fibroid but the sonographer didn't seem to be concerned. I just can't stop worrying and I'm now worried it will take away the excitement and joy from the experience! I'm also booked in to check my weight and I've always been self conscious about my weight even more so now I'm pregnant I'm worried that because I've been eating/drinking high sugary contents that I've put on so much weight! I got weighed at 16 weeks and 6 days and already put on 2kg's! Okay rant over needed to try and get it out so I could try and sleep again!