TexasCHLforum.com

IANAL.
It's called disparity of force. In your condition (OP), you would be at a considerable disadvantage against even one relatively healthy assailant, so you would (likely) get wider latitude with a jury (or grand jury), if it got to that point. It is the same idea behind a 100 pound woman drawing her gun on a 250 pound attacker. He could easily cause her serious bodily injury or death with just his bare hands, and she is very much at a disadvantage without the benefit of a firearm.

In any situation where a gun is drawn, you ALWAYS want to be the first one to call the police, because the first one to call is generally considered to be the victim.