There’s something wrong with Aunt Diane- I have a different theory

One of the more interesting takes I've heard on this case is that "inexperienced" drunk drivers are typically overly cautious rather than driving aggressively or recklessly. More experienced ones, on the other hand, would likely have been caught driving drunk many times before.

I think it's pretty clear that:

A) Diane was highly inebriated.

B) She was experiencing some kind of pain, hence stopping at the gas station looking for aspirin.

C) She was behaving highly irrationally. Why worry about a headache when you intend to kill yourself? Why drive the wrong way on a busy highway if you DON'T intend to kill yourself?

If Diane's actions had been willful or deliberate or premeditated - if she was either a secret alcoholic and/or was suffering from depression or other mental illness sufficient to make her want to kill herself - why hasn't more evidence of either one been brought to light? It's one thing for family and friends not to have known what was going on beforehand, but with hindsight, various people and agencies investigating the case, and so on, I feel like stuff would start to come out, and to my knowledge it really hasn't.

Here's my theory, for what it's worth:

Diane inadvertently has too much to drink, but doesn't realize how intoxicated she is until after she gets on the road. This might be even more likely if she WASN'T a frequent heavy drinker, as she may have misjudged her tolerance and/or not realized that, considering her weight, it might take longer for her to start feeling obvious effects of inebriation.

In addition to erratic behavior, this causes her to become very ill and/or develop a splitting headache. She's either too proud to call up her husband or somebody and say, "I need you to come pick me up. I'm drunk," or she's not thinking clearly enough to do so. Possibly some combination of the two.

Desperate, she pulls into the gas station and tries to buy some aspirin. Failing that, she tries to soldier on, eventually becoming so ill that she's forced to pull over and vomit. The kids are calling people outside the car who are no doubt ringing Diane's phone off the hook as a result, so - again not thinking terribly clearly - she leaves her phone by the side of the road rather than just turning it off or something.

Finally, violently ill, in pain, and all of this probably exacerbated by the fact that the kids are no doubt crying and panicking and raising holy hell in the back seat, she makes the impulsive decision to drive onto the interstate going the wrong way and end her life.

/r/UnresolvedMysteries Thread