If you feel the need, at any point in a relationship, to tell someone 'if I die/disappear, my significant other did it', then you need to get the hell out of that relationship.
I've seen too many true crime shows where the victim said or wrote those words, but they stayed in the relationship anyway and wound up dead. And, sure enough, it was the significant other that did it.
Thinking that your significant other may, in fact, kill you - enough that you feel the need to tell someone to look at them for the crime - should be a flashing neon sign. Don't tell yourself you're being silly. Don't pretend you're just being paranoid. Hell, you might be paranoid, but that doesn't mean someone isn't out to get you. Ya know?
It's your flight instinct at work. Listen to it. Run away. Run away.
And stay alive.