......do read this article by Harrison Barnes before taking such a step! It's a long piece, and is based on the author's knowledge of the U.S. legal job market, but a lot of it is relevant to the U.K. too.
His advice is practical and insightful.
There are many different ways in which to practice law. I mention just one option in my blog "There's more than one way to be a lawyer" - http://blogs.lexisnexis.co.uk/futureoflaw/2015/04/theres-more-than-one-way-to-be-a-lawyer/ - but the law touches every aspect of life and you can find a way to make practising law a happy experience (unless you're one of those Harrison Barnes says should get out, of course!!!).
The people who most often quit the practice of law are the people who should not be quitting. I see attorneys from all sorts of major law schools and from large law firms quitting because they got a bad taste of practicing law while working in a huge law firm. Conversely, attorneys from smaller law firms, the government, public interest organizations and other organizations—quite often with lesser qualifications—very rarely quit. This has led me to the belief that people who most often quit are simply in the wrong environment. If you are considering quitting the practice of law, the odds are pretty good that you should not: You are in the wrong environment and need to make some changes to that, but you should not give up