Door - as a boundary, they represent feelings you use to shut others out of your life, to remain independent or private to being open or inviting. As a passageway, they represent going from one state of consciousness to another, or from one inner plane to another. To dream that you are entering through a door, signifies new opportunities that will be presented before you. You are entering into a new stage in your life and moving from one level of consciousness to another.

Black - the color of the subconscious, of sinking into the darkness, or mourning. Black is masculine; it is the color of night. Black stands for limitation, hidden things, despair, depression, things that are considered 'taboo', conservatism, old age, melancholy and sacrifice(the giving up of things to make you, or someone else happy), your shadow (an aspect of your personality that is hidden, unknown and/or repressed within your subconscious mind).

Costume - suggests that you have, or someone else has,  created a facade to disguise your/their real self.

Vampire - suggests that you may be feeling overwhelmed in some areas of your life, and you're struggling with negative thoughts, feelings, and actions. You may be currently concerned about ethical or moral issues and are experiencing anxiety as a result. The vampire represents personal attributes or negative habits that drain energy and resources or cause emotional exhaustion. If you are being attacked by a vampire, you may perceive yourself as a powerless victim. Identifying who, or what, the vampire represents may help you to identify the source of your negative feelings and helplessness.
Also, to dream that you are being bitten by a vampire, signifies your need to shut out a person in your life who has been using you. It is time to open your eyes and stand up for your self. Do not let yourself be manipulated and played for a fool.

Shooting/Shot - a fearful and violent dream experience. It may reflect aggression, powerlessness, release of strong and dangerous emotions, and/or symbolize a conclusive event in a particular situation or relationship.

Blood - Life's energy source. Love, passion, anger, and life itself...a vital part of our physiology and it may symbolize our strengths and weaknesses and our physical, emotional, and/or spiritual energy health.
If you are currently experiencing a very difficult time in your life, you may have dreams with bloody or frightening images. Don't worry, you may just be venting your fears, and emotions.

It sounds as though you feel confused by someone in your waking life. That someone is pretending to be something they're not, just to please you. It could be that you're feeling drained and confused by all the emotions that you're going through.

Is your boyfriend, or someone else, asking you to do something you're not prepared to do?
Is there something you are trying to hide from someone else?
Has someone asked you to keep a secret, and it's bothering you?

Hope this helps, good luck!

Oh well my theory was that you had been watching too much Buffy against the vampires