His children are lying about me

Sheila

so today I found out that my boyfriend of 6 years his child is telling her mother that I slapped her in the face when I never laid a hand on her!! this also isn't the first time that they lied and said I hit them 2 years ago their mom called CPS on me cuz they said I hit them starve them and don't let them use the bathroom of course nothing came of it because CPS investigated and seen there was nothing going on. but now it's happening again and I just don't know what to do. how do I feel comfortable in my own house now when they're around on the weekends? my boyfriend says that he doesn't think that I would do that but he still has to talk to her about it which upsets me cuz I feel like he isn't sure if I'm telling the truth so I'm feeling attacked. I know better than to put my hands on another person's child especially when two years ago they said stuff about me then. I'm just so hurt and I don't know how to handle this. any advice or even comments would be appreciated. I'm seriously scared they're going to call CPS on me again and I'll have to be investigated again.