Should I leave or WALK AWAY?

I have been married to my husband for 4yrs. He has two outside kids 6 and 13 and one with me that's three. Its been hell!!! My step daughter mother died when she was two and the family is out to get us. My stepdaughter is bad *** hell she is six and has been kicked out of fours schools. Her aunt called DSS on my husband and I saying that I beat the little girl. Which was later found out to be a lie and DSS dropped the chargers.The aunt is always taken us to court to get custody because my step daughter gets a check every month. My stepson has a different mother and we do not speak. My stepson is very disrespectful and also have behavior issues. My husbands makes excuses for the kids. His family is very rude to me and do not like our child that we have together. We have split up many of times because of all the issues that we have but I really love this man.I have a lot of hate in my heart towards him, his family and kids.I fight my husband sometimes. He makes me feel that everyone is more important then me and my son. I have asked my husband to give custody of his daughter up so we could have a life. Every six months the aunt is taken us to court we can not afford a lawyer.. I lost my job 4 months ago and I was the bread winner in the home. I asked my husband to leave the home over a argument and he did leave. Since he left two months I found out he has been dating and sleeping around. I started dating out of hurt but stop because I knew it was wrong. This man gives me 400.00 a month on bills and I have around 2000.00. I feel like nothing,and so disrespected. Please help me to move on.