"I feel my stomach tighening up and it feels stressfull and negative."
Can you see a reason to drop this thought?: "I guess that he got my message and didn't call me because he won't want to see me and decided to move on"
Is there a stress free reason to keep this belief?
You are only attaching to a thought and look how bad that feels and what it does to your body!
Close your eyes, imagine the same situation, you wanting to make this phone call and you could NOT think that thought: "I guess that he got my message and didn't call me because he won't want to see me and decided to move on"
Who would you be, sitting there without the abilty to think that thought? How would you live your life differently?