To expand on what George_1950 is saying, make a list of the activities and environments you've really enjoyed and found energizing in your first job, in school, and in your leisure life. For each of them, ask yourself: what was it about that activity and environment that I liked? Then write that down. Now do the same with activities and environments you've really loathed and found draining; what was it about them that you loathed or found draining?
Your lists represent what you should look for and avoid in your career search. That's different than what you're good at or potentially could be good at. For example, you might really like singing but might be tone deaf and have little hope of ever pursuing a singing career. But I believe that in most cases, if you really desire to pursue a path, you will find a way to do so.
A great starting point for career exploration is the Self Directed Search, one of the most common instruments used by career counselors. It looks at your preferences in six dimensions, and matches against a database of thousands of other people who have taken the test. It returns careers that people similar to you have found fulfilling. You can take it online for 9.95USD at
this web site. It will give you suggestions for careers; each will have a DOT code associated with it that looks like this: 187.117-058. You can enter the codes on
O*Net and research the job. Most of the information will be helpful, except for the salary and employment information which is based on statistics in the USA.
The other dimension that would be useful to look at is personality type; your job satisfaction will be based on personality as well as preferences. For example, you might like the outdoors but if you're an extreme extrovert a job as a forest ranger where you're sitting alone in a tower all day probably wouldn't be a good choice. A good resource for this is a book called Do What You Are; I don't know if it's available in the UK or India - it is available through Amazon. If you know your Myers-Briggs type the book describes job characteristics that are congruent with your personality and provides lists of jobs for you to investigate (which you can do through O*Net). The book will help you determine your type, and the
authors' web site provides a free test and short lists of jobs associated with your type. Here's another
free test that will tell you your Myers-Briggs type.
Regarding failure, remember that many different people failed before they succeeded, sometimes repeatedly.
Here's a page that lists some of them.