This is generally referred to as flooding, and is in most cases a fairly ineffective way of learning to tolerate something you find uncomfortable.

Desensitization is a more gradual process in which you slowly introduce the uncomfortable thing, while staying at or under your stress threshold. My T and I are doing this as a way to help me talk about certain uncomfortable things. It started with her simply asking me about it...which resulted in panic and dissociation...and then we changed the subjected. Slowly, we worked up to me being able to tell her "one true thing," then talking for 1 minute, 3 minutes, 5 minutes, etc.

I use desensitization a lot in dog training, and the priciple is sound for both dogs and people. In dog training....say a dog is afraid of car rides...we'd start by having the dog sit next to the car and get rewarded for that. Once the dog is happily sitting next to the car, we'd sit IN the car and reward for that. Then, we'd sit in the car, turn on the engine, let it run for just a few minutes, reward. Then, increase the duration of having the engine run....then, we'd back out of the driveway and reward for that...then drive around the block, then a 5 minute drive, etc. The whole time, you're watching the dog to make sure that they are staying below their stress threshold, or just at it, but not going over. Thinking can't occur when the dog (or person) is significantly over their stress threshold. You keep each session short, and don't move on to the next step until comfortable with the current one. If you move too quickly, and it results in going over the stress threshold, then you just back up a step and give a little more time at that step before moving on.