I've had both hypersomnia as well as tremendous anxiety surrounding driving, so I really feel for you there.

The sleepiness could be due to a thyroid condition (I was tested for this) or some other physical ailment, even just a virus your body is fighting.

It could also certainly be the result of depression and anxiety, considering your other symptoms.

I would tell the doctor that you've been sleeping more than usual and yet are very sleepy during the day. Do you think you've been crying because you're worried and/or distressed about the sleepiness itself, or because you're sad/depressed in general? That's an important distinction to make, in terms of what you tell the doctor as well.