Jeffju, if you want to go back and try again, you should-you must take all the chances you can otherwise you might regret not taking them.
You might be able to get funding for a course or a loan for career development. This might give you inspiration :
http://www.learndirect-advice.co.uk/helpwithyo urcareer/jobprofiles/. You should think hard about what type of career you wish to pursue before you undertake any courses. There are lots of people who feel they let themselves down-I know what it feels like.A way to overcome those feelings might be to change what you do in the future, and not dwell on the past or what might have been. I wish you the best of luck in your future endeavours.