What kind of condition is having difficulty dealing with a loss?

Maybe none. Each person grieves in there own unique way. It could be someone else is saying that you don't grieve the way they do. On the other had, trouble dealing with a loss could indicate that the person is becoming depressed and not just grieving. Talk to a professional to help you figure this out.
More info pleas. It is difficult to give a good answer based on your question. What kind of loss are your describing. Please repost so you can get a better answer.