Exposure therapy will work for 99.9% of people if done correctly in conjunction with emotional processing of the event being exposed to.
Yes, when you do exposure therapy, you should have significantly heightened symptoms, suicidal even, etc. The difference is, is that you shouldn't be in hospital, because that means your not focusing enough on the process and what it achieves, instead you're getting caught up in the symptoms. Look at the end aim and desired result, not the symptoms.
When you go through exposure therapy, you should only be focused and reassuring yourself that it will lessen again, which you know, it will improve if done right...
Exposure therapy is useless if negative stigma is still attached to the traumatic event itself, specifically if targeting fear based events attached to the trauma vs. fear based events from social anxiety or isolation, exclusion from life.