You can’t do anything about your ex’s addiction issues. That is something he must tackle in his own time.
Meanwhile just focus on being the best mum possible to your little girl. She’s getting to that age now where she will be playing and talking a lot more.
I think its great that you can trust your ex enough to be in the same house but like the previous messages suggest, a family centre or a relatives house (where you don’t have to go maybe) would be better for you 😀