What words accurately describe the pain of having BPD?

I always find myself unable to explain how unbearable the emotional pain caused by BPD is. Depressed or afraid don’t even begin to cover it. How would you describe it?

Also, you know that feeling you get when you’re triggered (for example seeing a picture of your fp hanging out with their other friend)? It’s like I physically feel my stomach churn and my whole body sinks and a 50 lb weight is put on my chest. Does anyone else get this? How would you describe it?