welcome to SR, i am glad you are here, but very sorry for the events that brought you here.
you are right, meth is evil. i am glad that whatever it took, your BF is in a treatment facility now. this gives him a fighting chance.
and it leaves you standing in the smoldering embers wondering what the hell happened??? and what do i do NOW?
you get help for YOU. as partners of addicts, we take quite a beating, but we hold it together somehow, and even when they have been utter jackwads, we often clear a path to treatment FOR THEM. and then find we totally forgot to get some help and support for ourselves!
please take the time to read around at other posts, other forums, and pay particular attention to the "stickies" at the top of THIS forum. they have lots of valuable material for you to digest and absorb.
treatment isn't going to fix him. treatment is NO guarantee that he won't come out and use again, either within days, weeks, months or even years. he will be different as a getting sober person.....and he's going to have to do A LOT of work. that won't leave a lot of time for you. and that is going to have to be ok....because it is what it is. that is why it is best to dive into your own program of recovery NOW.....there are many types to choose from, often Alanon and/or Naranon are good places to start.
be an asset to your OWN recovery. let him own his. and know that there is the possibility that your relationship might NOT survive all this. you reserve the right to say when enough is enough. you both will need to heal individually before any real repair work on the relationship can occur......and that takes time.
so first things first, take care OF YOU!