Bad dreams and nightmares are extremely common after suffering from some form of abuse or any other traumatic experience. In many cases, the dreams and nightmares are a person's psyche attempting to work through the emotional and mental scars that the trauma from abuse causes.
But when the dreams and nightmares become extremely bothersome, interfering with a person's ability to sleep, or spilling over into a person's daytime thoughts and emotions- then there's a problem. If you've been abused in the past, or suffered from some other form of trauma, then it's perfectly normal to have dreams or nightmares after the fact.
While many people find that journaling, meditation, art therapy and other forms of self-expression help them to deal with their nightmares- it may become necessary for you to seek outside help in the form of a counselor or therapist.
Be cautious when choosing a therapist or counselor, you want someone who will take your dreams seriously and try to help you to get to the bottom of what's causing them. If you find yourself uncomfortable with your counselor or therapist, then it's perfectly acceptable to find someone else. It doesn't do any good to see someone if you're uncomfortable around them or they don't take you seriously.
As far as dealing with dreams and nightmares after abuse, it is possible to deal with them on your own. But make sure you don't dwell on them, don't allow them to take over your daytime "awake" hours.
To help deal with dreams and nightmares, it's a good idea to keep a dream journal.
This can be a simple spiral-bound notebook, a "fancy" locking diary, or some other type of notebook or journal. You can write in pencil, pen, marker- whatever works for you. Keeping a dream journal can help you to keep track of dreams, possibly figure out what external stimuli is causing your nightmares, and even help you sort out your subconscious feelings about something. This can be a real help when trying to heal after abuse.
Journaling in general can help you heal from abuse, and can help stop dreams and nightmares while you're trying to heal.
The more you write, the more you release onto paper, the easier it becomes to "let it all go." The reason for this is because the very act of writing symbolizes a "release" of sorts. It's easier to let something go in your mind, if you manage to vent (whether verbally, written, etc) and let it all out.
Meditation is another way to help you deal with dreams and nightmares after abuse.
Never underestimate the power of clearing your mind, visualizing yourself healing, and just in general calming yourself. If you choose meditation, make sure you have ample time to relax, plenty of peace and quiet (although soothing music at a low volume can help one relax without overwhelming them), and make sure you won't be interrupted.
Ideally, meditation as a way to deal with dreams and nightmares should be done right before bedtime.
The reason for this is because you can fully relax, let your mind wander without being caught up in the "dream state," and you can prepare yourself. Saying affirmations and giving yourself positive reinforcement (such as "I will have peaceful dreams tonight," "My dreams have no power over me," etc.) can help you to get relaxed and help prevent nightmares.
Often, nightmares and bad dreams are caused by physical stress, mental stress and other forms of turmoil in one's life.
For a person who is recovering from abuse, this can just magnify the nightmares and make the very idea of going to sleep at night stressful. The biggest key is to relax. Try to remember that the nightmares are simply that, bad dreams. They aren't going to spill over into your waking life or your physical world.
With time, a little patience, and finding a little peace within yourself, nightmares after abuse will usually stop.
If you find that the dreams or nightmares get worse or aren't getting better with time, then it's important to get help from a professional, as this indicates unresolved issues that you may need help coping with. Realize that your nightmares aren't real, even if based on something from the past, and you can deal with them- just like healing from any form of abuse or trauma- it will just take time.