Raped by my husbands Brother-in-Law

I seriously need help, I don't know what to do! 
So me and my husband have been married for 2 years, we have a 4 year old daughter together. 
Recently, my husband's brother, in law, Phil, has been coming over a lot and my daughter has taken a real shine to him. 
I'm gonna cut to the chase here, basically, Phil, sexually abused me 3 days ago, while my husband was upstairs putting our daughter to bed. 
He forced his fingers inside of me and tried to kiss me, he covered my mouth so I couldn't scream and said he'd kill me if I ever told anyone.
Since then, he hasn't come over, and when he's asked to, I've made excuses so me and my daughter don't have to see him. 
I don't know what to do, I don't want a rapist anywhere near my daughter, but I don't want my daughter to grow up without a mother. I also don't even know if my husband would believe me :( 
What should I do?