So My Boyfriend Has Been An Intravenous Meth User On

So my boyfriend has been an intravenous meth user on and off for 15 years. He is 41 years old and I am extremely worried about his health, both mental and physical. Physically, he gets meth"sores" where he swears the meth is coming out of his skin, some of the things he tries to show me, I see, some I dont. But the scariest of the physical problems is his heart, which I dont think can handle much more of this drug. After he does a shot, especially a big or thick one, 3 out of 5 times he gets chest pains and sometimes when I feel his heart it will even be beating irregularly. But lately its gotten to where he gets the chest pains anytime, like when we were driving the other day and he said it felt like someone had kicked him in center of his chest. I could tell he was trying to downplay the amount of pain he was in, but the look in his eyes told me how scared he really was. He also gets these stomach cramps in his groin in lower abdomen that radiate from his prostate, which he thinks is swollen. Occasionally, when he goes to the bathroom to relieve his backed up bowls, the pushing sometimes makes him ejaculate a little (not the good feeling, just the release of small amount of semen). Also, about the past 6 months or so it has slowly began affecting his vision, steadily getting worse and more frequent. When he first explained it to me he said his hands would get small, like a childs. It would happen to other things as well, an object like a cigarette, or even my head, would appear ridiculously small to him. After all the googling i did of his symptoms, the one condition I found that fits him exactly is Micropsia. Which is kind of scary because it can be caused by many things like drug use, a brain tumor, or even hallucinations. Which brings me to the next issue, hallucinations, both auditory and visual. To make an extremely long story short, everytime he is on meth, he has hallucinations so severe ive stopped him from juming out of our 3rd floor apartment window, because he was convinced he heard and saw 3 men planning to break in, so much so that he even called the police twice. I have seen him have a one sided conversation with someone that wasnt there for an hour before. And this is all coming from the most logical and level-headed person I know, when he is sober. The voices used to be after a few days up, now they are almost always there, and he is never sober long enough to see if they stop after the meth is out of his system. The voices usually start out as background music he can barely hear (this happens to me as well), eventually escalating into him hearing a voice that is narrating his every move and criticizing him and saying cruel things. Or the cops listening or following us is another. You would think that with all these scary, traumatizing things that have happened, it would be easy to quit. But no, being an addict keeps us doing the same thing over and over, the same thing that is also slowly killing my boyfriend. Please help me, how do I convince him to quit when he's quit before in the past, for years at a time. But he also knows that it is something that you need to want for yourself and he just doesn't want it right now. This is not only my boyfriend, but my best friend and my partner in crime. I always grew up thinking that the perfect kind of love should be a certain way and he makes it that way. I couldn't imagine a life without him in it. The main thing I want to know is can his physical and mental health come back from all these different things that are tearing his body apart?