Being a step parent

I have a step child whose mother is a completely usless you know what! She didn't see her child for 7 months of his life! She had to quit the drugs because she caught wind of having zero rights to her child after skipping court 3 times! Of course the court system is fucked and orered her visits 2 days a week. Ever sense I have been dealing with non stop drama all revolving around him! I know its not his fault but I can't help to get irritated with all my problems revolving around him. Someone help!