10 ways to say - I'm worried:
1. I'm (so) worried about. .
2. I'm afraid. . .
3. I can't help thinking. . .
4. I can't stop thinking about it.
5. I've been worried sick about. . .
6. It's been keeping me awake at night.
7. I'm scared stiff / to death that. . .
8. I'm really nervous.
9. I've got butterflies in my stomach.
10. I'm absolutely dreading. .