I am struggling with time management and I feel like a failure

So I got a job as a self employed bookkeeper. I have 14 clients right now and I am struggling to keep them up to date and on time. I feel like I need to quit my current position. I am working crappy hours. 10-12 hours a day. At least 5 days a week. Sometimes more. There have been times when I worked 20 hours in one day, 12-15 hour days, 7 days a week for weeks on end. I have been a bookkeeper for 20 years and I feel like a horrible failure at managing myself and time management. I am starting to doubt if I truly want to be a bookkeeper. I am thinking of starting a new career but I am 41, have 2 kids, a spouse to support, and the knowledge that a new career will be difficult. <br><br>I am considering going back to a regular job in an accounting department as an employee but the advancement opportunities are not good. I will never be able to be a controller or CFO because you have to know everything and they are too busy doing their job to learn. <br><br>I am just lost and feeling like a failure. I pay all my bills on time but I want to make more money and I thought being a self employed business owner would be the best way to make more money. I am not afraid of hard work but sometimes I feel like I am not good enough. I get these stupid panic attacks that I need to get everything done right now! It is frustrating, and it is not good for my mental health. <br><br>I am not sure what to do.