Almost ran someone over

Kinda crazy title but it’s keeping me up at night
I struggle a lot with focusing and details my whole life to the point where it’s what I’m known for by everyone
I got my license in January and everything has been okay except that I often start to daydream… especially when I start to drive after waking up
It’s gotten quite dangerous, running stop signs, pausing before an empty roundabout and today the light turned red while pedestrians-green. The man started to cross and I didn’t see him and drove straight through
By an actual miracle he reacted fast and jumped back
Weird how I never have these issues in the evenings, instead I lose focus on everything else but driving
I know, very shitty, and I hate myself for it I genuinely feel so bad
My point is that despite agreeing with myself to never drive before lunch time again, the guilt is eating me alive I can’t sleep because I actually could’ve killed him
How do I deal with this overwhelming guilt? The moment is over and I’m still getting intense heart rate when I remember every hour
Also do I have adhd? Or is unstable focus a normal thing no one talks about