You should not stay.
It’s very difficult to be in a relationship with a drug user who sees you as a barrier between him and his drugs. Addicts have a primary relationship with their substances and everyone else comes second. That’s why you feel manipulated — because you’re less important to him than his getting his way, and he’ll manipulate and lie to do so. 😳 If you want to be with him, you have to understand that you will never come first.
I appreciate that you love him but you don’t want to be with an addict, and my suggestion is that you love him, but don’t date him. Not everyone you love is right for you, and you can still love someone — and if you REALLY love him at the purest level, you’ll want to do what’s right for him, not just what makes you feel good. True love involves sacrifice and it’s important for addicts to be with people who don’t enable them, and who can use boundaries and say, I’m not going to be with you if you’re using. I love you, but this is what’s right for both of us.
Basically, you have to rise above what you want and do what’s right. 😉