If your current psychologist doesn't understand how serious it is, can you try again to explain? If you become like a different person when you have a rage attack, he would not have seen that "person". I used to get overwhelmed with rage sometimes. I could "turn if off", at least temporarily, by going numb and "stuffing my feelings", but that's not the answer either.

I didn't really understand it myself, so when I tried to explain to psychologists they didn't get it, either. And when I got enraged at a psychologist, to try to "express" my feelings rather than turn them off, the psychologist reacted in fear and didn't know what to do! My understanding at the time was that getting mad was "bad" but I did not understand that, or why, the psychologist would react in fear because I had numbed out or dissociated from my own fear reaction to people's anger due to childhood trauma.

Eventually I found a specialist in trauma and dissociative disorders who has helped. And now I understand but I didn't then.

I'm not sure that an inpatient evaluation would help but if your psychologist still doesn't "get it" after you try again to explain, can you look for another? Also looking up "rage" and "rage treatment" on a search engine may bring up some ideas you can relate to.