How do I stop eating my feelings?

So something happened at work on Thursday and I have been trying to put it out of my mind and pretend that it has not affected me.

I had a customer come in to meet with the lawyer I work for and myself on Thursday. Now this man has told me on numerous occasions that he was not well, has a heart condition and recently had a stroke. He wanted to come in to discuss a legal matter involving his property and I have put it off for a long time because of his health issues, but he insisted to come in. The three of us sat it a boardroom discussing the situation and all of a sudden he started to have an angina attack. He had his nitro spray and seemed to settle down and then boom he had another one. I managed to keep it together in the boardroom, but as soon as he left (after he was feeling a bit better) I retreated to the washroom and broke down in tears, it was so upsetting partly because my Grandmother had angina and had a massive heart attack and died in front of me. This was quite a few years ago and I realized that I never spoke about that experience, never dealt with it and this experience just brought everything to the surface. I have spent every day since then pushing the feelings down and numbing myself with food.

I need to deal with the pain of both experiences and let it go so that I can move on, I just need to figure out how to do this.