I think my aunt has a mental issue?

i have a 4 yr old son i was a bad mom for the 1st 2 yrs of his life i pretty much left him with family and did my own thing now i am doing everything i can to make up for the mistakes i made and especially for lost time my aunt seems to be trying to prevent me from getting close to him he will ask to sleep with me and she will say no u cant but then a week later ill come home from work late and she'll have him sleeping in her bed i think in some sick way she doesnt want him to like me more then her everytime i try to have like a personal moment with him she always has to chime in or be present she can never just let us be alone i hate it how can i show him im sorry and fix things if she wont let me also if i say something about it to try to get her to see what shes doing she trys to say everything is my fault and if he's bad its my fault also she sometimes treats him like he's 18 instead of 4 in that she discusses with him grown up issues not appropriate for a 4 yr old like court cyf things like that how can i fix this please help me!!