My advice would be there's no harm in trying.
Fact of the matter is, whilst grades are of course important, they're not the be all end all. Lot's of people are offered places even though they don't meet the grade requirements. If you're worried, have a backup uni that requires lower entrance grades, but is one that you feel would still suit you. A lot of unis really do value personal statements, so of course it would help strengthen your application if you perhaps gained a few days work experience for example to include in there. You need to show that you're committed to the subject - that's the main thing.
Whilst a back up uni is an option, another option would be to simply delay your uni application another year if you find you don't meet the grade requirements to get into the uni you'd want to attend, and retake exams so that you do attain the necessary grades. There's no rush to attend uni, however that is a personal preference which I do understand.
Always apply. Definitely don't not apply because you're worried you may not get in. The only chance you'll have of getting in is if you do apply!