If you sit down to meditate thinking about why you can't relax, you probably won't relax. If you sit down with the intention to allow whatever happens, you might just find yourself relaxing.
Some people come to meditation as if it is a task to "do" or even to "complete", perhaps a product of a competitive culture. Of course these people find meditation more difficult. Here, alone with your thoughts, there is nothing to do; here nothing will ever be complete.
Seated in meditation, you are free from any demand. You do not have to achieve anything, do anything, or be anything. You are free to enjoy the process.
Read the transcript and important notes here: Enjoy the Process