Dealing with anger / overwhelming feelings at the time they happen

Hi all,

Its been a while since I last posted anything. I have spent the last few months reading, and avoiding writing anything while I have worked through some things. That's all something for a different post though, possibly one where I lie down on a couch. 

My main subject is dealing with anger and overwhelming feelings. I have been through some workshops on mindfulness, and coping with feelings, and they all seem to work on:

• Focusing on the now, and clearing the mind,
• Then assessing the situation from a calm and neutral place, before making the right decision.

However I am struggling getting to the point where this can work.

As an example of what I mean:

I was eating with my wife and two of my children at a local food chain. It was early in the day and quiet (I only ever go to eat at places when they are not busy). The food was nice, and I managed to stay calm throughout, even when the kids started to behave as kids do. It was nice, and I went to pay the bill. When I paid, I thought it was slightly to much at the time, but I am useless at confrontation, and started furiously doing maths in my head, even as we left. Very quickly it became apparent to my wife that I was having some trouble containing my emotions, and asked what was up. I explained the cost and went through the receipt, to which she was surprised as well, but the food had been nice, and it had been a one off. We had planned to go on into town, do some shopping and enjoy the rest of the day. However, I was so angry, and overwhelmed by everything, I started to shout at people not stopping for zebra crossings, using language I feel terrible about in front of my own children. I shouted at my wife for no reason, and then got stuck inside a debilitating bubble of feelings in my own head that led to 3 hours of silence, covering the walk back to the car, journey home, including a stop to the supermarket, and back at home. 

I am aware of how I did not do the right thing in the situation, and am also aware that by breathing slowly, counting to ten, focusing on the now etc. are proven techniques to calming people down and resolving problems. I just cannot prevent the rapid escalation when something happens that I have not planned and is out of my control. I feel terrible for my wife, as often she is left with an extra child (me), and I feel ashamed that I leave her to deal with it all. I prefer to stay at home, or do things I know, or go to the same places at the same times to avoid issues etc. and keep things as I know them. 

How do other people deal with that initial wave of emotion? Are there any other techniques that people have tried that work? 

Many thanks all,

Daniel