How bad is Gastritis for you?

I'm asking this because I was diagnosed with gastritis before, but on Friday at 2 in the morning I woke up with horrible pain, like in the middle of my chest that went into my back.
Kind of what it feels like if you were to swallow rocks. Pain level like a 7 from 1-10. (I have had diverticultis so I know pain)
It got so bad that i wasn't sure if I was having a heart attack, it hurt to breath in deeply and it hurts into my back. I went to see the doc short notice, and he did a rather quick check with the stethoscope and pressed around and said its a bad gastritis, to take the proton pump inhibitors he had already prescribed earlier.
I didnt quite believe him, to be honest, cuz I can't imagine gastritis feeling this horrible. But the PPI actually helped, it's Saturday afternoon and it is slowly getting better.

Is this really how bad it is?
All I am doing is sleeping, trying to drink tea, eating congee and dealing with a headache.
What is it like for you?