Hi Lucy,
I am so so sorry about your partner… There are no words for what you must be going through right now. You need someone to talk to, and there are people who are able to listen and understand in some way to perhaps help. The Icarus Trust is all about supporting families who have a loved one involved in addiction, this might just be the ticket for you right now. You can contact them by either going to http://www.icarustrust.org or via info@icarustrust.org.
I wish you all the best.