Dealing with Disappointment

I am guilty of many things. One of them is not handling disappointment well. I often come across is mad when really I am just sad. I do not know how to change this. I do not know how to traverse disappointment well. I have a hard time not internalizing disappointment or thinking that some how it was my fault. My default reaction at that point is to put up a wall. It is "easier" to be alone in my hurt than try to make things work. That is extremely selfish; I know that. I just am a broken person doing broken stuff.