The best advice i can give you through my own limited experience with opiate withdrawls (i've done a Cold Turkey once in my life, after a 3 week heroin binge) is clear your schedule for 1 week when uoi are planning coming off/running out.
Also might be worth getting some cocodamol in or codeine pills in. Have plenty of easily made food in. Like make a mac and cheese or some other easy to get down food that will last you 2-3 nights on the last day before you run out. Make sure you are in comfortable as possible surroundings with a bathroom close by lol. Plenty of easy to watch viewing lined up for the TV, as you will likely be in bed for most of the week.
Last but not least be mentally prepared. And when it starts, the pain sets in, and your mood drops real low, remind yourself 'this is the withdrawal talking i will be better in a week'. The hardest thing for me coming off heroin or pregablin was the mental aspect. My mood just dipped so much. If you can control the mood by telling yourself it will pass the whole process is much more bareable than if you fall into the mood and start believing that's your reality now.