if i report my boyfriend to the police will they force him to give me back my passpor

he seems pretty confident that i’ll only get myself into trouble if i do. hes being such a ****. i swear he liked me better when i was depressed. now that i finally want to live my life instead of being stuck at home, it’s suddenly a problem, he can’t stand that i’m no longer trapped in this ******* house 24/7 for his convenience.

Yeah, that's called false imprisonment and it is a crime.
Call the police or the non-emergency number at 101.
Why are you staying with him if he does stuff like this to you?

what if he lies and says i've lost it or that I’m crazy? can they actually do anything? it's defo not in our house.
he's not bad, he’s done more good for me than anyone else ever has. but he thinks he owns me.

If you tell the police what is going on exactly, they will take you seriously and he could be looking at charges if he doesn't comply, which I know you probably don't want, but it would be more to scare him into giving it back rather than to actually get him in trouble.
If you are happy I won't question it, just always make sure there is a door if things start to go bad.

i have very little faith in the police but will see...

Why?