One thing I could suggest is to talk to them about how they make you feel.
If it is really bad then I would suggest to be extremely kind to them no matter what. Always respond to the negativity with something positive. This takes time, but it can work and I've seen it work. You have to be patient.
Another approach is to get involved in positive activities where you are not around your family all the time. Some are free, some cost money, but they are out there.
Last, you can always talk to someone, like a friend or counselor to help you with this difficult time. Someone mentioned to journal which is helpful.
Remember, it is temporary. that is the most important part. One day, you will be out of there and you can choose whether or not they can be a part of your life. I believe your "true family" are the people that love you and treat you right and bring out the best in you. Find those people and make them a part of your life!
Best of luck!