If you want to drop out of university, its up to you, at the end of the day your an adult and can make your own decisions.
If you unmotivated and depressed and you think university is the problem, then its best to go with your feelings and instincts.
I know its hard trying to identify what you can change to make yourself happy again, maybe moving closer to home will be the best option for you and a course you want to do, but it could be that you still like the subject, but because of the homesickness and demotivation that you temporarily lost interest in the subject.
A lot of people on here have dropped out, all it takes is a simple search, or a google search and you will find a wealth of information. You shouldn't be scared about not getting into another university as you have been accepted before, and nothing in your ability has changed to cope with university work.
The hardest step is doing the dropping out or suspending, then after that you can think about moving home, maybe getting a part time job or volunteering to occupy your time until you want to go back. You could even do some study with the open university if you wanted to maintain focus on studying.
If you feel university isn't going to be right for you next september, don't worry, there is no rush to get a degree at 18/19/20, loads of people do it past this age.
23...30..40..even older.
At the end of the day,
-you could apply for next year's entry
-you could take a few years out to decide and make sure you are happy before you start again
-you could maintain focus by reading and distance learning
-you could work and volunteer to occupy your time
-you could study via distance learning