I can't seem to get over my girlfriend's drug use.

When she's high, I can't trust anything she says about anything. I hate it. I've caught her lying before, and she comes clean when she's off the drugs. She also gets really defensive/emotional and likes to start shit by basically being high.

The thing is, I indulge every once and awhile, so telling her to outright stop would be incredibly hypocritical.

She has a cousin who basically pushes her to do all these drugs, more so recently, and of course my girl just can't say no. I asked her why she just won't say no to her cousin, her answer was a combination of "who cares? school is starting soon so this is my last chance" and "i can't say no to my cousin she'll feel bad blah blah bullshit".

I guess she'll stop when school is in session, but only because she won't have the influence of her cousin around. Her cousin is a manipulative, controlling, psycho, drug addicted bitch from hell whom is bent on ruining our relationship because she can't handle not being in complete control of my girl. My girl does not see how easily she is manipulated by her cousin, but if I bring it up to her, nothing will change and I will only cause drama and look like a complete dick further strengthening her cousin's hold.

I care about her. She is only hurting herself and our relationship by doing these drugs and being pushed around by her cousin.

How do I get her to stop? Or how do I get the fuck over it?

Some more info for you:

She has a problem remembering shit she did or said or w/e when she's using. No matter what it is, she seems to have blackouts.
I on the other hand, never have blackouts, and don't lie to her even if I'm on something.
So trust is an issue, and that specific about the drug use isn't being a hypocrit because I'm open.

OD her with meth

its quite simple

kill her cousin and problem solved

Just dont hang out with her when shes on drugs? Or take drugs when you're with her, that way, you'll be to fucked to care.

What does she use?

Answer this.

Then, be reasonable: Asking her to stop is unfair and hypocritical. But let her know that you don't trust her cousin, so ask her for a compromise: She can do what ever drugs she wants, providing you're by her side.

If her cousin is really as bad as you say, I wouldn't be surprised if she was that little devil on your girlfriend's shoulders when it comes to cheating as well.

I'm guessing it's heroin.

She is or will be or has been the little devil on her shoulder, I'm pretty sure when it comes to cheating too. Its inevitable, and if her cousin died, our relationship would prosper.

But I don't have trust issues with her cheating because she would be throwing away our relationship if she did, and therefore not be worth my time or effort. Yea it would suck, but at least I would know where she stands so it wouldn't be too heartbreaking.

She uses everything under the sun, except heroin and cocaine. Its never consistent on what she's using, its usually whatever she can get at the time.

If she's also not using meth, you're being a giant fag about her drug use. Maybe. It sucks that it's fucking with your relationship anyway.

She obviously genuinely wants the drugs though. It's not entirely the cousin.