Not overly difficult really. Just be up to speed on Trigonometry, transposing formulae and the like. Physics? It isn't too hard, if you have done a brush up then you should be fine. Just so long as you have a basic understanding of how the forces in flight work with or against each other and so on. Read Kermode etc.
I didn't pass maths or physics at high school (I did a year later at technical college) so if I can do it, believe me, any one can.
What people find difficult with the ATPL is the sheer volume of work and piecing together the systems/engines/performance aspects.
Met often catches people out so start watching the wx on telly with a bit more interest. Ie note how the cold/warm fronts move and so on. Also, the movement of the ITCZ is a very useful thing to have bolted.
If I were you, I would concentrate on stuff that you may not see. As I said, go to a maintenance hangar and have a look at what an alternator looks like, how it's wired into the engine, prop governors, even a battery if you haven't seen one. To be able to picture it is worth a thousand words in a text book.
Maths and Physics? That by comparison was easy.