How do you stop yourself from yelling at a parent if they're yelling in your face?

The same as with anyone yelling at you. Stay calm, wait for them to finish yelling, give them a bit of time to calm down. Then ask them if they would likely to calmly discuss the issue they were previously shouting about. Remember that if you start shouting it will just get worse and the issue will not be resolved. This will likely lead to repeat shouting in the future.

Immediately think of what you would've done if it had been a teacher yelling at you. Remember that it was most likely to benefit you, and if not, don't take any actions. Wait until they are done yelling and you both have calmed down to think of a correct way to dissolve this issue. You will feel much more mutual in the end.

Take in a deep breathe and just let them know you are trying your hardest and that you understand where they are coming from.

When I say respect in this regard I do not mean that a parent deserves respect /over/ you, this is my opinion, anyway. It is within my opinion that all people, young or old, are equals and should be treated as such within appropriate and proper limits of respect and knowledge. Fairly, sensibly. Now, in the world of parenting it seems that as parents, there is a certain sense of control over their child that is still acceptable amidst most people you likely talk to about it. Many people may still say that the parent will always know better or that they have every right to yell at their child or scold them or even hit them. I want it to be noted that my opinion is taking the individual affected as first priority in this message. All that said, with all things considered, it is my personal view that the best thing you can do is this: understand that you are not inferior and that while your parent may be slightly misguided in yelling at you with such ferocity, being cordial in the face of that behavior is a testament to your own strength of mind and body, anyway. Not to mention, when you can add to that a sense of love, regardless of how you feel about your parent as an individual (that is, you may not love them in the traditional sense) you could still love them in a way that is as seeing them as the equal you know yourself to be to them and therefore act like it. See them as their potential and not what they are presenting moment by moment. See them as a whole world unto themselves, as you are. Remind yourself that people make mistakes and that there is no end to growth and learning, not at any age. Remind yourself that all things are temporary and that after the fact, after the yelling and whatever else, time for yourself will be at hand and finding yourself once more in a quiet space to regain your integrity and wellbeing will be worth it. You are worthy of it. It will be a good idea to do so if you find yourself affected by being in this position. Find your center and realign, reimagine, and know that everything is OK and will be OK. Whether it happens again or not. Respect given is also respect gained. Respect cannot be taken but you respect yourself by respecting others. You lift yourself and strengthen yourself by respecting and understanding a far larger story than one fearful, angry, (so forth) version.

When your parents yell at you try to calm yourself down, having in mind that situation isn't as severe as they are coveying it to you. Then when your turn comes, answer to them as calm as you can and don't let yourself to become irritated or angry if they continue to scream or yell at you or if they make you feel defeated in any way. Try to stay calm and accept that you can't win every time and that it is ok not to win the conflict or situation. If feeling of weakness or helpless arises, have in mind that these are just feelings and not facts. You aren't weak and you aren't helpless. By staying calm when they yell at you you show them that you have got self esteem and that you don't get hurt by their yelling and that any intention to hurt you by them won't work in you.