Exam advice

Hi, a recurring issue I have found with A levels (I do maths, FM and physics), is that I can either get the answers done with the right method, but inaccurate answers due to some arithmetic error and be done in time, or be more quality over quantity, and get more answers fully correct and complete, but at the expense of time, meaning I can reach close to the end of the paper, but not fully complete it. This is due to my horrific handwriting (My parents think I might have dyspraxia because this has been an issue my entire life), but this is a particular issue at maths + FM A level, due to them demanding more careful tracking of values + method marks being a thing, because before I could just do it in my head, but I need to write it all out now. How should I practice, with past papers or otherwise, to get high quality answers done in good time? Because I can do the maths, but I then screw myself over because I either misread what I write or cannot read it at all. I was in writing classes between 8 and 14 ish years old, so have no clue what to do because I cannot get a word processor at A level unlike GCSE.