Nothing is ever good enough Ugh?

Why does it feel like anything I try and do is never good enough in her eyes I have explain how I feel about our family relationship that we have had for 6 she said I have always been family but doesn’t feel much like she is my family her 2 boys are super close with me I spend more time with them then she does she will say I can take them anywhere I don’t have to ask ask long as they are good she doesn’t care but then she will say you have to put it past me first I have talked to my mom but she doesn’t seem to understand why she is doing this I don’t wanna keep wasting my time making the effort here to do things I spend 500 or more a week on those 2 kids I don’t feel appreciated at all I told my mom we should move but her oldest doesn’t want me leaving this is our second time living with them cause the first time living with her was complete hell and we couldn’t do it anymore how do I know if I am being used just to do things for them and not being a family member if anyone can help with this please do