I know this all sounds negative to you but please listion to the others.... RUN, run for your life, your sanity, your safety and your well being..
Your BF has already proven to you that he will use you to get drugs.. They always have a sob story, an excuse and a lie. He will keep coming back to you as long as you give him money and take him to buy his drugs.
Relationships with an addict are one sided.. An addict is not capable of giving you a healthy relationship. They cannot love you because they do not love themselves, they cannot respect you because they do not respect themselves and they can not be available to you because they are not available to themselves.
The best thing that you can do for you is to cut your loses and walk away from him.