I think therapy would be good for you, its important to be considerate for the people that took you in, my Nan fostered me for years. My mother was severely mentally ill, so us kids were taken in by our grandmother. I learned a lot from Nan, and she holds a special place in my heart. It must be the same for you, my Nan used to beat me over cold coffee, i made for her. I still love her even though at times she took advantage of us. The people took you in and provided for you, its important to love them and forget about their wrongdoings and try not to take them personally.