Divorce is not the only way to formalise the end of a marriage, though it is right for the overwhelming majority.
Judicial separation
This is a court order recognising that you live apart while remaining married. It suits people with religious objections to divorce, or who married less than a year ago. It does not allow remarriage and does not give the court the same financial powers, in particular no pension sharing.
Annulment
Annulment says the marriage was void or voidable, for example where one party was already married, the parties are too closely related, or consent was not genuine. There is no one year waiting period.
This article is general information about the law of England and Wales, not legal advice. For advice on your situation, speak to a solicitor.