Thanks to your friend but hope you know she won't always be there for you? This is why you need to take responsibility for yourself.

You really need to check that habit, it can be undone, you know habits come into existence through continuous practice, if you want to undo it, you will use thesame principle, start disciplining yourself to keep to your words . If possible draft out a plan every month for it so that you can trace your progress.
And as you continue to practice how to say something and work on it, and how to stay from unnecessary spendings . Try this out, it might help.