Some kids just have a harder time in the morning. If he is getting enough sleep and you don't think that is the problem I think you have the right idea. No cartoons until he has eaten and dressed.......maybe let him eat in front of the t.v. as a reward to being dressed and ready to go. Some people have trouble eating first thing. I understand you want him to have nutrients in the morning. Would going to bed 1/2 hour earlier and getting up 1/2 hour earlier help him to be in the mood to eat? He may need a little time to zone out. What are his weekend habits?
Don't freak out. The worst that can happen is that he will be late. Let the consequences fall at school. Better now, than in High School. In fact, you could go and talk to the teacher and discuss it. Agree on appropriate consequences, like staying after school to make up work. Don't let her chastise him in front of the other kids and Don't take away recess.......I hate that. Kids need a break during the day. If you can agree with a reasonable consequence with the teacher you don't have to be the bad guy or jeopardize your relationship with your child. If you are yelling at him every morning he is probably tuning you out and feeling he can't do any better. However if you work it out with the teacher, and have an appropriate consequence at school......not only will you be off the hook but the natural consequences may do the trick. Right now there are no consequences other than being yelled at. We've all done it, but it really doesn't help.
I'm a type A too E.. My second child zoned out and never considered the clock. I learned a lot from him! I'm much better at "letting go." Try rewards at home and consequences at school. Keep home happy, not anxious. I didn't always accomplish this, of course, but it sure is nice when I do.
Also, a big clock, or setting a timer helps too.
Good Luck and enjoy!