My first question here would be: Are you currently in therapy? If not, I would highly recommend it.
This very much sounds like both intrusive thoughts and a pretty harrowing impact of you needing a yes or no. Many couples have multiple ways of showing the other they consent to having sex and focusing on some of those may help.
You say you’ve been reading articles about rape and that it “all seems so subjective”. Rape isn’t subjective, rape is one person choosing to force an act on another, it’s usually very clearly defined.
I can understand your boyfriend’s stance here regarding you being the one to initiate sex. You’re showing him that the boundaries between what is and isn’t sexual assault/rape are blurred in your mind right now, and that can be a dangerous position for the person you’re having sex with to be in.
I would say this is absolutely that bad and that your current obsession with rape, researching it, hyperfocusing on it, is really unhealthy. I think you need to talk it through with a therapist, personally.