Your comment about the UK thinking you're well enough if you're asking to go in made me think of the novel Catch-22 by Heller.

Wikipedia sums it up nicely (I was trying to and falling all over myself with words): If one is crazy, one can be discharged from the army. But one has to apply for the discharge, and applying demonstrates that one is not crazy. As a result, one will not be discharged.

I hope you're able to get the help you need.