I think the majority of people do... no one likes to end things once they're attached. I am one who has struggled with it my entire life. Finally I know what to look out for, what I like/dislike in people and once you figure that out, it can make it easier to walk away from a toxic situation...once you've experienced & healed from the pain it can bring, you should have a natural reaction to stay far away from it or the red flags waving in your face. its totally normal though... but what isn't normal is putting yourself through a ton of pain and sorrow. Give yourself some credit by justifying the way you feel and walk away.
surround yourself with people who love and care for you... there will be painless nights but every day you get a little stronger...
hang in there