At first, the title may seem to be either too simple, or lacking the understanding of what problems can be like. However, it is so true. You simply will find it too difficult to solve problems when you are so overcome by worry, either for that particular problem, or in general. Understanding this further will require some explanation.
Think back to a time when you may have been panicked, or in a state of great concern. How did you feel? Were you able to think of any clear move to make next? I think I can say with safety that the answer is no, and this is common. Primarily, the reason for this is that no one can think clearly when in a state of panic, as the body is effectively in a fight or flight mode. It is true that not all problems will create the degree of anxiety I am describing here, but I wanted to express a starting point.
Now, consider if you are not as panicked, but in a state of constant fear, or worry about things. It is natural that your very being is affected, and you will not be thinking any where near as clearly as you could be. I hope to address this problem, and provide you with some insight into releasing some of your worry, to allow a free flow of thought, for greater creativity, and problem solving ability.
Whilst it again, may seem overly simplistic, the very essence here is that you need to learn to relax more. I fully understand this does not make the cause of the original problem go away, but it does provide you with the ability to effectively, release your mind into a free thinking mode, where creativity can once again, enter the equation, and assist you to arrive at a desired solution to your problem. This is possible, as your primary worrying is now somewhat under control. Again, I would like to emphasise that I understand you may feel frustrated at this suggestion, or think it is so obvious, it is nearly stupid.
I can only ask you to genuinely consider, and then, action this point, as only through action, will you see the results that you so understandably desire. However, it is your level of desire that will also resolve your problems, and further, help you deal with your worry.
I can understand you asking yourself if this is all there is to it, and the answer is yes, that is all. The technique, or secret sauce is in controlling your worry, and by that being taken care of, the rest will fall into place, as you will be free to be creative.
