I have fairly bad issues with claustrophobia myself--I've never had to get off a plane, but I have had to get out of various vehicles due to panic attacks or impending panic attacks (a van full of people where I was stuck in the last row, several very packed subway cars). I am unable to travel if I am in the window seat in a 3-3 configuration, even on a full-size jet--I will willingly swap places with the middle seat holder, just to be closer to the aisle. For me, it's the combination of being confined in a small space (like an airline seat) and being unable to escape to a larger space (e.g. the aisle) that bring on panic attacks.
Panic attacks are unbelievably scary and unpleasant. I will go a long, long way and endure pretty much any level of embarrassment to avoid having one. I don't blame the OP at all for requesting the stairs to be brought back. If you have to, you have to.