Should I be concerned about my step mom?

We are from Vijayawada. We are a small family with MOTHER FATHER 2 SISTERS(ELDER AND YOUNGER) AND ME (ELDER SON above ALL) My mother died in 2000 and my father remarried. Its been 15 years since their marriage. One year before my grand father died. Then things changed a lot- like 1.) Few Months back my step mom's Elder sister's Son came here to work here.(Village to Town) 2.) She looks after him and feeds him on time. But she doesn't even ask us to eat. 3.) Some days before they are in some conversation and this guy from village is working in a Car shed. They want to give him a property just for a car shed after 6 years gaining experience. 4.) They doesn't even know to keep silent when some one in a room is sleeping. They shout and speak very loudly. 5.) I am on a JOB SEARCH in Hyderabad.After my grand pa's death they changed into grandpa's room. They haven't allotted me a room or a cup board. 6.) They are giving my clothes to him. Once I asked her to buy a pair of sandals. She denied and said. Ask your father after coming from office. I nodded and THOUGHT ITS OK. 7.) She doesn't even given me 3 rupees for a biscuit packet when I'm hungry. They used me to work for their building renovations like small small works like plumbing and cleaning. WHAT SHOULD I DO???