You sound like you need to relax.....have you tried valium?
Alright, lets remember that as well as banter we're also here for srs drug-HR business.
annaiilyzii, have you sat down with your boyfriend and confronted him when he's sober with what he's been doing? I'm sorry if this is obvious and something you've already tried, but if you've explained he's been throwing you around the house, breaking things and tried to kill your cats and yet he carries on then you're looking at one of two things IMO: either he's a dick, and I would escape if I were you (appreciate it's not that simple, but if someone is wilfully carrying on despite knowing he is hurting you..) or he's an addict and it's up to you if you feel you can stand by him and try to help him get treatment or not (if there's a danger to your safety then it would seem sensible to at least get some physical distance, perhaps by moving out?).
If you're going for the latter, the key is he has to want to make changes too, or it's just going to be frustrating and futile for you both. Flushing his stash will sadly probably make him angry and frustrated and feel you aren't on his side, but sometimes if someone is seeking treatment you can come to an agreement that if he will absolutely not take it in your house/presence, and if he does you flush his stash and do what you need to do to be safe, or something along those lines.. ideally it sounds like he needs to be shooting for total abstenance though
you can get help from your GP, or there are various agencies such as Narcotics Anonymous or other local/national agencies (try
http://www.nhs.uk/Livewell/drugs/Pages/Drugtreatment.aspx )
If he's not addicted (it can be hard to tell, this doesn't just mean physical addiction and I'd argue that there is going to be at least some psychological addiction going on here) then I think you need to be firm about this - if he causes injury to you or frequent/unacceptable damage to the house then you need to decide what the consequences will be. I think if he carries on then you need to remove yourself from the situation