Whenever we become hysterical with worry or doubt, this is typically due to the same cause. We are not paying attention to what is actually happening. To overcome this problem, we need to find ways to continually return the mind to what is happening right now.
For instance, if we are out walking, we can bring our attention to the fact that we are walking, or we can become aware of our surroundings and the temperature outside. Paying attention to these things does not need to be focused because simply knowing that things are a certain way is the essence of mindfulness.
If we become skilled in bringing our attention to the way things are now, then we will quickly realize that all our problems are either in the past or in the future. The present has nothing for us to fear.
However, when the mind strays from this reality that is when suffering will come in. If we understand things this way then we can identify the real problem. Instead of blaming our suffering on our future prospects or our regrets, we can see that our actual challenge is keeping the mind in the present moment.
Once we know the problem, the solution becomes apparent. We have to train ourselves in mindfulness. Then we can learn how to be happy with the way things are and there is nothing that could be more valuable.