Could be the Crohn's itself.
It's official: Crohn's disease makes you stupidBut certainly, PTSD on top of that will not help.
Suspect I'm affected in a similar way, but there's nothing I can do about
it. No meds help me. I'm all right with driving, but struggle with parking - it seems to require so much more concentration and skill to park in a bay barely wider than the width of your car than it does to drive. Often I'm feeling frazzled at the end of the journey too, which doesn't help with the parking skills. If I can, I'll park further away where there are more empty spaces, but sometimes there isn't that option.