That's the trouble I found.
You make £5k one month and spend £3k.
You run into trouble when you're only making £2k and still spending £3k
A little more trouble when you break even and spend £3k
The month after you dip into your bankroll to pay expenses. This is also the month you lose money.
The next month you're spending £1k, most of it on credit, and playing $10 tournaments.
Poker is fun.
I did pretty much exactly that over a slightly longer period. It's easy to lose motivation and focus especially when other parts of your life start to interfere.
I went back to work for a few months before all the money had gone. I made sure I got my head and my finances in the right place before I went back to playing full-time. I'm now a lot more cautious with my bankroll requirements and I keep a closer eye on my money generally. Going back to work was horribly depressing and I'll too all I can to make sure that if I ever return to the employment market then it will be very much on my own terms.
If you have a crappy job and you can easily find another if it goes wrong, then it's worth a go, but make sure that you are properly prepared with a plan an established winning record and a big pile of money.