Am I overdoing it? Am I being overambitious about my A-levels?

dedication has no limitations

If you think it's manageable then by all means go ahead. How are you predicted 5 A*s if you're doing 4 A levels though?

I know you've set a personal goal but you should think about whether or not there's any use taking 6 a levels when all you need is 3. A*A*A* in Maths Physics and CS is guaranteed to get you into any uni course (at least grades wise).

You've taken Maths subjects so I don't see the point of EPQ, as Oxbridge really don't care about EPQ.

3/10. The bit about Oxbridge gives it away

I completed my AS-levels last year and got 4 A's in Maths further maths, physics and compsci.
For A-levels im taking:
Maths (A-level), Further Maths(A-level), Physics (A-level), Computer Science (A-level), Additional Further Maths (AS-level), EPQ (AS-level) and I am Mathematics helper (super-curricular), also I'll be taking MAT preparation classes at my college after schools for an hour and a half once every two weeks.
This means of my 30 lessons a week, I have about 7 blocks free.
It's a lot to take on... Im hoping im not digging myself a grave.
I asked my predicted grades and its only my maths one that I really had to debate with about being predicted an A* for further maths... but im predicted respectively to each of the AS/A-levels.
A*, A*, A*, A*, A, A*
I will also be sitting MAT in November, the Mathematical Olympiad in December, STEP in June.

I hope the predicted grades give you an idea of what kind of a student I am.. I realise my mistake last year was to work hard and not smart despite still doing reasonably well...This year will be mental in terms of difficulty and Im worried im overstretching myself.
I plan to do a 9-7 day at college as I have special permissions to stay in college to work.
Am I crazy?
What do you think? Am I overdoing myself? I found I finished all my 6 maths modules quite quickly last year (by end February) and Physics I kind of kept up with as we continued, always staying ahead of the game though as I was worried we wouldn't finish on time. Computer Science was ENTIRELY self-taught with no teaching.
My teachers think I'm crazy to try and do so much and the only reason I am doing so much is so that I can prove I'm smart to myself really and that I can cope if I put my mind to things. And also I want to make a competitive application to oxbridge even though oxbridge really doesnt matter that much to me.