at first foster kids can be angry , sad , or they can hurt themselfs but know that it wouldn`t last a few years. if it does last a few years than i have some tips for you that might help.

Many foster children have experienced traumatic experiences, such as abuse, neglect or maltreatment. Other foster children have regularly witnessed arguments and domestic violence. Out-of-home placement is also usually a traumatic experience for a child. Because of their 'backpack', foster children are often in a state of chronic stress. Chronic stress has a major impact on the brain and brain development. These children become hypersensitive and are almost constantly anxious. As a result, even small stimuli sometimes elicit strong instinctive fight, flight or freezing reactions. Many foster children are hyper-alert, which makes them easily distracted and easily overwhelmed. They are quickly overstimulated because they absorb much more stimuli than an average child. When a child experiences too much stress, it will adjust its behavior because it constantly expects difficulties. How does a child do this? By trying to control his environment. We then see: constant movement, being rebellious and asking questions all the time. There are also children who do their utmost to always show sweet and adapted behavior in order to avoid difficulties. Traumatic events and chronic stress can cause a child to behave in one of two ways: the child becomes busy, aggressive, defiant and defiant or the child becomes quiet, lethargic and withdrawn. Combinations of these behavioral problems in foster children are also possible. One moment the child is busy and rebellious, the next moment quiet and withdrawn. Often the child also develops additional problems, such as anxiety disorders, depression, mood disorders and sleep disorders. These children sometimes also have learning difficulties due to their poor concentration and poorer working memory. It's not that these kids don't want to do their best or "don't want to obey." Their behavior is a result of too much stress in their body. In order to recover and develop, they need foster parents who educate them in a trauma-sensitive way. Your foster child is not a manipulative, attention-seeking, stubborn, rebellious, uncontrollable, and defiant monster. It's just a toddler in disguise (brain development wise) full of emotions, low self-control, low self-confidence and low confidence in your abilities. Threatening consequences, dictated solutions, time-outs, and other punishments add stress to the child.I accept that the difficult and unwanted behavior stems from how the children feel and their limited development. you could try to talk with the kids about how they feel. if they let you , you can give them a massage to  help them relax. the `problem behavior` can slowly go away because the child doesn`t have to think about it all the time. if this doesn`t help you can talk to a children psychologist to see if the child has other problems.

i hoped this helped you :)