I was in a similar boat to you. Took three exams, didn't take them seriously enough, and failed. A few years later when my life was a little more stable I retook the exams and passed all four in a row. I also started with BEC, which for me was necessary. While BEC is really tough, it is the easiest of the four and requires the least amount of study time. I took BEC first cause I just wanted to pass an exam to start my 18 month clock and give me motivation, and that worked for me. Once I saw my passing score for BEC I was ready to pass the other three! So while the popular opinion is start with FAR or the most challenging, I personally disagree with it simply for the motivation reasoning.
I only used Roger and found it more than adequate, though with REG maybe something else to supplement it with practice questions might have been nice, but obviously by my scores it wasn't necessary. Simply what I did, was I watched each Roger video, then read that material (For example, I'd wath AUD 1.1 then read 1.1, then watch 1.2 then read 1.2, etc.). I took my time, re-read tough sentences/paragraphs, and took lots of notes during the videos. I pretty much wrote everything down that Roger wrote on the board and some. I also would take a practice exam after each section and any question I got wrong I'd find that material and go over it again just to make sure I got it, and even questions I eventually memorized I worked from scratch and followed all of the steps so it'd stay fresh in my mind. Didn't do anything besides that. And finally, I studied a lot! I pretty much spent all of my free time studying. I'd come home from work, eat dinner with my wife, then study until bedtime. On Saturdays I studied all day literally, except for a break for meals and about a 30-60 min walk if the weather permitted. On sundays I took a morning break for Church, but as soon as I got home from Church I'd study all day except for lunch and dinner. That's all I did, study, study, study. It sucks, you'll miss your family and friends, but unfortunately that's the only way to pass, is to put in the many hours.
If I can do this, so can you! You got this, and you will pass and become a CPA and as Roger says, find out what true happiness is all about! Good luck and remember it's all worth it in the end!