URGENT i need help with my brother who is on drugs!!?

ok well my mother passed away when i was young and she left me my brother and my sister a house (all paid) so at the moment me my partner and my brother are living here. My brother is on heroin he use to be on it but he quit for a while but his back on it, my partner and i cant stand living there and seeing him like that but i cant leave because i just got there and me and my partner didnt want to rent again and try and save some money. I dont know what to say to him for some reason i dont want to make him feel bad or get him upset i dont no why but i just cant. its really sellfish of him like last night i was out at my friends house having a girls night then my partner rocked up and i was shocked to see him and he tells me that his sorry but he couldnt stand staying there because my brother was pacing around the lounge room then went out to score then came home going through all the draws and my partner said oh are you hungry ill cook us something and his like nah where are all the knife and forks and that.. and my partners like in the draw and he grabbed a spoon went to his room and 20 mins later came out and was nodding of in the loungeroom so my partner just got up feed the dogs and came over to my friends house. i cant be botherd with this **** i hate coming home now i worry that he'll steal our stuff or o.d. and i dont no what to do but i cant live with it anymore please anyone who has been in this situation before any advice?