Having knowledge on a subject like bereavement is helpful but processing the grief is much more than knowledge.
I am personally very smart. I don't like to toot my own horn and rarely tell people that I have a high IQ. I also know the stages of grief and knowing the signs and being able to handle them are two different things. It can often feel like standing on the railroad tracks in cement shoes with a train coming at you as fast as possible. The train is coming and you know it's going to get you if you don't get out of the way but at the same time you can't get out of the way fast enough to not be hit.
Most of the time when things are coming the best thing you can do is get yourself to a safe place where you can be comfortable and have support to get through it. That can mean heading home and going to bed or finding a quiet place. It could mean being in a situation where you have friends and loved ones around to help. Everyone deals with grief and loss differently so how they deal with it will be as varied as there are people on the planet.
You have to find your "safe place" for yourself and do your best to utilize it when needed. But remember that it's not always going to be feasible to drop what you are doing and head to your safe place. I personally found a lot of help in talking to random people as well as posting here for those who need the help. I am truly a wounded healer and want to help others through their grief while also helping to relieve some of my own grief as well.