Leaving a marriage is very stressful, but the better you are prepared, the better you will be to survive this stressful time.
Knowing that the marriage is over and deciding to leave is the first step in your recovery from the stress of a bad marriage. Some stress is good to have, but the stress due to a bad marriage causes all kinds of negative consequences including health problems.
Create a post-marriage nest egg. Gathering the courage to leave involves not only some soul searching, but also the stockpiling of money in a bank account so that you can pay the costs of a new place to live. If you expect to remain where you are, you will need enough money to cover the bills yourself when you ask your partner to leave. Sign off any joint accounts and open your own checking and savings accounts to deposit money as you prepare.
Stay focused. Supporting yourself is much easier when you have a job. Not only can you afford to maintain your lifestyle, but having a job also keeps your mind focused on something other than the end of your marriage. Staying focused in those first few months is essential so that you do not return to the bad marriage just because you think it was better then being alone.
Indulge your interests. Getting a new hobby or going back to an old hobby is also helpful in keeping busy and focused. It does not matter what the hobby is as long as it makes you feel good.
Rely on your support system. It's important to have and use your support system of family and friends who you can talk with, go to the movies with or just grab a cup of coffee. They will help keep you focused on moving beyond your bad marriage.