I Need HELP Now! How to take/study A-Level??

Hi, everyone I'm need help!
I'm from Malaysia, Asia. I earnestly ask for help/advice/opinion?

The thing is I've only half completed my secondary schooling(till the third year). So I do not have any secondary education certificate. The highest qualification that I have is till primary education.
I wish to further my education abroad to UK to study compsci.
Before that I need to get A-Level qualification. I've chosen my subjects
Maths, Further Maths, Physics and a Foreign Language as the fourth subject.
I had also mailed the uni and asked that do I need a secondary education qualification(IGCSE/O-level/ or equivalent) before A-Level. So it seems that I does not need to have studied GCSEs in order to study A-Level.

The problem I'm facing now is how can I study my A-Level??
Teach myself? No, I won't be able to study on own/self study(it' not that easy and I've not study any a-level course before).

Hire a home tutor? Would I be able to learn/study all that I need as those students who study in a school/college? Does the home tutor teaches the same syllabus as those studied in school/college?
I'm worried about the coursework/practical too as I'm choosing science stream. Maths and Science is my main subjects.
Would I be able to take all the exams paper that I need to take? As I'm applying as a private candidate and I've heard some papers are not open to private candidate.

Study in a school/ college? I've check some colleges for A-Level but those need IGCSE/0-Level or equivalent qualification for entry requirement.

I am at a loss.
This is bad. What should I do now? What is the best for me now?