This can be a very, very dangerous thing!
I once dated a girl who got really fucked up due to the
unconditional love she had for her father, a father who abused that love. He used her as a toy, never gave her any guidance, and never showed her any love himself. How he tormented her made her crazy and insane, and due to the unconditional love she had for her father she was blind about the cause of that pain. That unconditional love can make you blind in such cases is why I think it's a very dangerous thing.
This one girl's father molested her. He would get her drunk or stoned and watch her stumble about as a way to entertain himself. They went to a zoo in Florida once when she was young: he picked her up, held her over the railing surrounding an alligator pit, dropped her into the pit, and laughed hysterically at her frantic attempts to climb back out. He only reached down and retrieved her when the prank grew tiresome to him. This same girl was full of stories of such torments, and due to her unconditional love for her father it never occurred to her that these were bad things. She thought the father was just a cool guy with a good sense of humor!
My advice is to never limit your life to just one person you love unconditionally. You'll be too blind to realize when the person is bad for you. Keep friends and other family members around to observe the relationship, and listen to them when they pull you aside and describe the warning signs they've seen. Be careful who you love.