On a global scale, a degree or a diploma can be all the difference in the world. However there are many jobs that don't require a higher education.
For example, I work in the food industry. You can rock up to any chef and ask him to teach you in exchange for you working for him for free and you'll eventually be a head chef one day.
In contrast though, I'm working on a chef degree because paperwork speaks.
Perhaps don't apply for university just yet and take a year off to find yourself.
Alternatively, perhaps you're approaching the subject matter wrong. Perhaps you're trying so hard to remember everything, you're not learning anything. Take a step back and run through the basics again. A few hours on a Saturday never killed anyone, and either way, working 6 days a week may be a reality for you one day anyway.