Always experienced it. I feel like I have a hole, or a weight on my stomach. It's a weighting sensation, but not a physical one. I have it usually when I'm obsessing over someone. It's not anxiety but it's similar. So I think it's anguish, it's this constant weight and inner pain. Like someone is stabbing me. I can't eat even if I'm hungry, I feel like my stomach is closed. When I feel like this I just want to get drunk or harm myself to escape from it. 

I don't know if it's really anguish. But I think yes. It's the worst feeling in my opinion... And I think it's here because I want to be with a certain person but I can't. I want to be with him forever I'm constantly daydreaming about him and I feel this anguish.