Once you finally come to a crossroads and make the difficult decision that no matter how hard you try and how long you stay that your partner is never going to change, you will start to look for a way out. With determination, inner strength and love for yourself, you will eventually be able to know when and how to end a hurtful relationship with as little heartache as possible.
Keep a clear head and try to think positively about how much better your life will be without the pain this person adds to your daily life. Chances are that you've tried and tried to make this work to no avail, and you have to accept that it is time for you to be happy again.
Listen to that little voice in your head that tells you to pack up and get out of this mess immediately. If you do not move fast, then your partner may possibly be able to convince you once again to stay. Your partner might tell you and even promise you that things will change, but you must not fall for this again as you have in the past. The fact is, if you really feel like this love affair cannot make you happy, then it's time to end it. Try to see it all as a lesson learned, rather than beating yourself up over time lost.
Remove yourself from the relationship and be indifferent to the whole situation. You will know that you are truly ready to move on once you feel nothing either way. When this person no longer controls any part of your emotions, that is really the end to a hurtful relationship and the easiest time to say goodbye.