Here's a short list of things I recommend when people come asking me what they should do about this or that or just want things to change and be different somehow. And plus, if you're into transformation, you'll just naturally enjoy these things. And if you have more, let me know, because I love spending time doing things that focus on transformation.
And I know, transformation can happen at anytime, anywhere so there's no guarantee, but at least people have tested these and have had results, myself included.
So before you quit your job or end your relationship or spend a whole lot of money doing anything, I would highly recommend you spend three and a half days of your life doing the Landmark Forum. And then I'd recommend you go down the line and do the other courses they have to offer. That is number one.
If, by chance, you have ten whole days in a row to yourself, I would highly recommend you sit in a Vipassana meditation retreat. There's nothing like sitting in silence in your own mental crap that will motivate you to clear some of it out like this retreat will (except maybe the Landmark Forum).
Doing a yoga teacher training where you examine your life and the yoga sutras, would be another thing that would produce results, almost guaranteed. So check for those, but you'll need more like a month off for that type of thing.
In terms of bang for your buck, I'd do the first thing - it's only a weekend. But it's $500. Vipassana is a longer time commitment but not a financial one. Your first course is free, or by donation. Yoga teacher trainings tend to be in the thousands of dollars, so if you've got time and money, that would be fun, plus at the end you get a certificate if you're into collecting things :)
If you want to read something that is transformational, today's recommendation is anything by Anthony de Mello, but especially the book, Awareness. His call to WAKE UP is loud and clear in that book and he doesn't mince words. (This video is what the book says too - I think the book is a transcription of this series.)