Modafinil was my gateway to harder drugs, but...I have bipolar tendencies and it gave me euphoria. The doctor who wrote this book says in it that modafinil is actually used successfully off-label to treat meth addiction, but that he’s had a couple of patients who got high off it and they were both bipolar. Talk to your doctor about this, especially if bipolar runs in your family.
Come up with a plan to stop using or, at least, severely restrict your use, and stick to it. You are showing warning signs of your life getting markedly worse, despite your obvious high intelligence and drive. The common denominator is a substance that you think you can handle. Nobody plans to jump off a cliff, but you are headed toward one. I'd recommend Russel Brand's book about addiction, even if you reject 12 stepping out of principle. One of th e first thing he says is the most golden lesson you can absorb when dealing with highly-addictive drugs: "Do you have a plan?"
Apologies if it seems like I'm trying to scare you or tslk down to you. I'm a grad school dropout who has made poor choices on meth-like substances, but I'm human and so are you. It's very hard to control your behavior on drugs that get you this high, especially if you fall into the trap of redosing, which is a feature and not a bug of most NDRI's. If you have to use, make it physically impossible to go on a bender. Keep small amounts and space out your usage. Get a timelock safe and throw away the key if you have to keep a stash. Get a calendar and track your usage. Write down the reasons why you use. Become familiar with your urges and behaviors (your witnessing one of mine that is unhealthy: the desire to "fit in" to communities by "helping" others). Learn how to substitute activities that are fulfilling (meditation is boring af at first, but it can help you see your emotions without acting on impulses, which is key). Drop friends who enable using and, when you are ready, talk to friends who don't use about your struggles so you can see what "normal" is. Be kind and forgiving to yourself. You will break your rules, but when you do...enforce consequences. This book supposedly has guidelines for harm reduction if you are going to use. If I ever fall back into my habit, which is likely because I know myself, one of my rules is "no using for more than one 24 hour period." (I have went on several days-long benders, and it wasn't pretty.) See the harm before the fun and nevet lose sight of the consequences of having too much fun. If you're like me, you are making these choices because you are hurting. I hope you are healing, too.
When someone tells you that you are imagining things that you know you are not imagining, it is a specific form of mental abuse called "gaslighting." Your partner who is using cannot help it, because the high amounts of dopamine in your partner's brain will cause him to lose touch with reality. Hence, what is normal, decent, and acceptable ends up being substituted with what is self-protective, selfish, and ego-driven. If your partner does not get help, then your relationship is going to suffer, and you are going to have to decide how much you can take. Physical abuse, frankly, should be the least of your concerns. Your partner is behaving in ways that are abusive, and these ways do not leave marks, which actually makes them far worse than physical abuse.
As shameful as it is to admit, I have been on the other side of this, so...since you do seem to want to salvage the relationship, let me explain that your partner is the one who is not living in reality. But he is a real person who is probably using because he is going through a lot of emotional pain and does not have an outlet (or...he does not have options that he wants; very few people make th e conscious choice to self-destruct, but highly potent NDRI's have a way of bringing about srlf-destructive behavior in even very smart and very strong-willed people). You need to tell your partner that he has a problem, that he has to face it, and that he cannot continue using if he wants to be with you. After this conversation, I would leave and stay somewhere else if that is an option, and let him know that he may contact you once you once he has made his decision. Then let him make his decision. The only way things will get better is if he wants to quit. Good luck. He is going through a downward spiral, and trying to save him will only mean that he drags you down with him.
During your time apart, you may want to read this book to help you understand what he is going through. Good luck and take care of yourself. If he continues to use, then he is not taking care of himself. As hard as it is to hear, in this addict's opinion, you should not be taking care of him when he does not take care of himself.