Use the time to expand your pool mind. Watch videos and really study them.
Seriously ... THIS!
If you spend 3 hours a day or more watching pro matches (all of which can be found for free on youtube, etc) and taking notes about their shot choices, then go practice 2x a week with those notes; you'll see more improvement than playing 3 hrs a day doing random drills or playing the ghost.
You can get there both ways, sure, but when money is tight, free is always a great option - and you can really get your mind in stroke, as well as learn things - for free!