Is something wrong with me or it's him???

Va

He always makes it feel like everything I do or everything happens it's my fault... We have a 3y old and 5 months old and my son is super hyper, very active boy, can't stay still and is very naughty most of the time, so my son yesterday hit my 5 month old daughter in a face ( it was kind of an accident) and she was screaming, obviously he got punished I told my husband and he said I'm sure she's fine, it was an accident don't be too hard on him, then today my son was doing silly things around his little sister and hurt her again and I said to my husband that he hurt her again twice today and he asked me how did that happen, I said I'm not sure, cause I didn't see that very second when it happened, cause our son ran away as soon as he hurt her and he said that he didn't if I didn't see it happened and said stop accusing him for no reason and he thinks I'm just overreacting... But am I? It's not about our son, it's about my husband, he thinks I'm a liar... He works nights and I'm alone with 2 kids almost every day, it's hard for me as I don't have anyone else to help me, so I'm a little sensitive and get angry or sad really quickly...