You told him no multiple times. You where even crying. It was obvious to him that you didn't want it. So yes that is rape and it is in no way your fault. Letting him stay over is in no way consenting to what he did. You are not weak. You were drunk and situations like this are scary. You're not alone and this wasn't your fault. The blame lies entirely on him. You could report him to the police if you want, but that is entirely up to you.
When a women says no, and a man continues, as this one did, it's rape. I'm not sure under the circumstances whether the way it happened would result in a criminal conviction. You've stated that you were drunk and high, and after this man made advances and you said "no" you continued to drink with him. You and he were both "weak" by continuing to drink when you were both too high to look after your own best interests. The fact that he cried, when you cried, sounds very much like he is a good man, but is not in control of his drinking and drug taking, same as you. I think the best thing you can do is to take responsibility for your own actions in this case. I know you said no, but you continued to put harmful chemicals into your body, making you more and more unable to protect yourself. The action of drinking and drugging, and having another man stay over, would be enough for many to break up. No one wants to be with a girl they cannot trust enough to not put themselves in danger of being taken advantage of. Whether or not you ended up having sex with another, while in a relationship getting drunk and high puts you in a very bad light from the perspective of a boyfriend. Same as if your boyfriend was to have gotten drunk and high with another girl, and offered her his couch. That's not what committed couple do. I'm not sure how old you are, it sounds like you may be young. You must become accountable for your actions, in order to learn from this, but you also must be good to yourself and forgive yourself for the mistake of putting yourself in a bad situation. It might help you to talk to an Addictions Therapist, if you are not able to control your drinking. If you can't go out and drink, without getting drunk, you have a problem. Unfortunately this type of problem often ends up with you being in this exact situation, over and over, if you allow it. So just chalk it up to learning from your mistake. Yes, you were taken advantage of, and in my opinion you were raped. I'm not sure that your boyfriend will see this as a rape though, he may just see that you put yourself in the situation to be taken advantage of and that could well be enough for him to want to break up. I'm sorry, just know that we learn from our mistakes. Everybody makes mistakes. If you've ever been sober, and watched a women get drunk, you see pretty clearly that it is not a pretty sight. Focus on not being that girl, and you'll move on from this in the right direction. I'm afraid if you continue on as you are, you will have more and more experiences as the one you just got through, and every time it happens it hurts you spiritually and kills self esteem. Please don't let that happen. It's your responsibility to keep yourself safe. There's enough risk in this world, without you becoming numb to the dangers. It might help you to find closure on this incident by talking to a therapist about your feelings, again an Addictions Therapist if you cannot drink without getting drunk. All the best, Onward and Upward!!