Hi AdamSt205, so far so good & best of luck with your PPL skills test etc.
First of all the UK/EASA ATPLs are a very different ball game to the PPL. It's the volume of high-class rubbish you shall never use again in the time available that's the killer for both for full-time & distance learning (DL) students trying to keep focused & motived isn't easy.
It is possible to do the ATPLs (DL I presume) in 9 months, I have known students (DL) do them in 6 but this is rare I believe the average is around 12-15 months. Don't forget there are limits on number of sittings and completion times from when you sit your first exams. Known several DL students running out of time or sittings as life & unexpected events get in the way & divert you off course.
Bear in mind different schools/ATOs don't all do the ATPLs in the same order or number of subjects in a module so that might have a slight impact. As others have said above don't attempt the exams until you are 'happy' and reasonably confident that you will pass first time with a good mark say 85%+.