Difficult in law

Fil is being super difficult especially when it comes to my toddler. Doesn't listen to me when I say don't give certain food.. Very traditional thinking, keep saying Abit is okay... Example, giving tea to my toddler and snacks when he's coughing. Husband always side him saying he's old, so just give in to him zzz. I still rmb during my confinement period, he kept insisting in giving my 1m old baby water. I can't even do my confinement in peace because it feels like I need to constantly be aware of what he's gonna do and all. Understand why my husband is like this bcus that's his only dad now. So he kinda side him more. But some things no means no. I feel so annoyed and irritated by my fil. Sometimes just come into my house without informing too. Don't know what to do, all the small little things are slowly stacking to my peak. Just feel anxiety whenever we need to meet him for dinner or insomnia if I know we're meeting him the next day.