I haven't done it but am hopeful I will be able to do something similar in the not-distant future. I have a great deal of respect and admiration for those who are doing it and those who have done it. But I have changed certain aspects of my life dramatically and can say that when the change is to take yourself to a better place, it makes the transition a lot easier.
Hopefully you've taken full advantage of any scholarships and grants you can possibly get as these might help take up much or all financial slack. You also have to decide what, if any, sacrifices you might be willing to make to ensure you are able to focus.
Based on your thoughts and conclusions above, I get the feeling you're going to be just fine.
BTW, I know of at least a couple of TFPers that are in school to make a career change. You are not alone!