Indeed, this is a very morally difficult situation for you. In addition to the answers given to you by the Clergy above, which are quite comprehensive, I would like to emphasize the following.
Your partner is in a state of voluntary enslavement. Cocaine and substances like it — are not just chemical compounds; they are Tools of the Enemy, designed for the Destruction of the Soul and the Blockage of any Spiritual Advancement. This isn't spread for no reason; it's a perfectly viable Tactic for the Enemy. A person following our Path strives for Perfection. You surely understand that drugs work in the exact opposite direction: they subjugate the Will, cloud the Mind, create breaches, Holes in the Aura, destroy the Chakra mechanism, and significantly impede a healthy Energy Exchange in the Spiritual Body.
This should be understood in the context of what was written by Lady Lidia. Your partner truly doesn't have much time to come to his senses. Because your partner isn't just «making a mistake»; he is committing a betrayal against himself, against his Divine Potential. He has traded the Work on his Soul for a cheap and fleeting surrogate for power, which is ultimately destroying him. The people who surround him — dealers and fellow users — are not just «a bad crowd». They are pawns of the Enemy's Forces who feed on his downfall. And your partner could very well have been guided down this path of self-destruction by the Enemy. They love to provoke situations where a Zevist hits rock bottom, while his Zevist circle remains helpless and powerless over it. What your partner has been drawn into — is a living manifestation of Entropy and Spiritual Regression. Keeping those who surround your partner at a physical distance is not enough.
It is necessary to completely sever all Energetic Ties with them, including those that pass through your partner. They are visible on the Astral, so I advise performing the Working only if you can perceive them with your Psychic Sensors. They can be cut, you can try to Program your partner’s Aura and Consciousness (Hypnosis is also an option, but it is difficult), reinforce the Effect with Affirmations, ask the Gods to accompany the Magical Process and do all of this during an Astrologically favorable period. This Working can be performed daily for a 180-day period, after the Full Moon and before the New Moon. The Working must begin during the Waning Moon Cycle. For this, you have to use the Mantra «TH», Focusing the Vibrations on his Chakras, Illuminating your Astral Instrument with a White/Golden Radiance. Then, to give the Working Power and Burn away all repeated attempts to form such attachments, you must choose a Sun Mantra: either SURYA or RAUM. And yeah, before the Working, you will need to Cleanse his Aura and Chakras throughout the entire interval, if possible.
But it is very important to stress here, to avoid any misunderstanding, that this is exhausting, difficult, and clearly not a panacea. It will most likely not have a Powerful Effect right away, if any at all. This is because your partner's Will is broken, which, in general, may allow you as the stronger party to «implant» the Program you need to restructure the Mental Forces of his Soul or even attach a Thoughtform to his Aura to guide him. However, your partner is incapable of being responsible for himself, and his addiction to cocaine is merely a consequence, not the cause, which lies much deeper and must be Healed either by you with the help of the Gods, or by himself. That is to say, what I have proposed above may well weaken such an Influence on him, but it is unlikely to eradicate it completely. He might find something else besides substances and will still be cut off from the Gods. In other words, you will simply be depleting the Energy Resources of your Soul in an attempt to save him, while he will be receiving a resource for his further downfall. In any case, what you can be absolutely certain of is that Protecting your own Soul is now your main priority and your direct Spiritual Duty. If you let him drag you down with him, you both lose. You must become an impenetrable fortress for yourself.
So, TG Blitzkrieg raised some rather important questions in his reply that you should answer for yourself. Is it worth it? Will it be a just measure? Is it worth saving someone, even if that someone is a Dedicated Zevist? For the most part, these are all rhetorical questions. Of course, you may love him, but that doesn't mean unconditional forgiveness, and you should consider whether you need such a partner and what to do next. Your partner's condition may not only be the Influence of Enemy Forces, but also a part of his Karma, which is very difficult to Influence and hard to Heal, and such outside interference can even be dangerous. I would also recommend that you Discern the answer in Meditation and in Communication with your Guardian or Satan/Zeus. Perhaps not all is lost yet, and the Gods will show Favor to your partner, and they will pull him out of this shit.
The question of whether to let him «hit rock bottom» — is a question about the Awakening of his own Will. An ordinary person only begins to fight when the pain of the fall becomes stronger than the pleasure of the addiction. By continuing to support him, to soften the consequences of his choices, including by Magical means, you are, in essence, preventing him from reaching that point. This is cruel, but it's the only real chance, if you are willing to take it and if he is worth it. You must present him with an absolute choice, an ultimatum: either he immediately and irrevocably chooses the Path of Strength, completely cutting all ties with his destructive present and beginning the arduous Work of restoring his Soul and Body, or he chooses his addiction, but does so without you. You must be prepared to walk away, and this is not a threat, but a statement of fact. Your Path — is a path to Nobility, to Goodness, and there is no place on it for those who have consciously chosen slavery and self-destruction, or have done so unconsciously but have no Intention of pulling themselves out of the shit, even with outside help. Perhaps it is precisely complete isolation and the realization of final loss that will force his Will to Life and Strength to Awaken. But the decision must be his to make. The Gods can help him, but you cannot do all the Work entirely for him. Your task — is to preserve yourself, your Strength, and your own Path.