Push / Pull and denial in full swing here.
The Push is what you experienced about the conversation where they stated you're texting too much. This is classic engulfment fears in action. You pushed harder, and pointed out that he was pulling away, and set a boundary. Then he left, and the abandonment fear kicked in, which resulted in the call that they're in physical danger, and at the hospital.
Maybe try validating the engulfment fears instead?
He didn't say I was texting to much the exact words were "this little app I have for daily quizzes gives me the same alert as your texts do and when you're texting me a lot and that app goes off It gets confusing" and he said it in a light hearted way so I tried to make a joke... .I didn't do right i'm sure but I thought since we had that light hearted convo and joking going on that it wouldn't be a big deal... .well I was wrong again but in retrospect I think you may be right about the engulfment and I shouldn't have fed into it
Is it common for a BPD to do things like that about being physically ill?
The only logical thing my mom and I and 2 of my friends, that I trust to give me honest advice and not just tell me to leave him, can come up with is that he was somewhat trying deflect from what happened earlier in hopes I wouldn't bring it up again since hes " sick"