This happened to me EXACTLY as your described. I'd just started hanging out with a friend from high school when I was raped and I told him about it some time later. After months of being completely platonic, he suddenly became more intimate, more caring and told me he'd had feelings for me since we were in school.
Nona, if you think he's at least a decent person, I can tell you right now he's wracked with regret and guilt that he can't show because he doesn't want to hurt you. Moids are emotionally immature and when my moid blurted that out to me, it was out of a misguided sense of affection; like piling on his love would somehow fix the pain I was in. Of course, he realised soon after how clumsy and stupid that was, and that he acted out of urgency to try to fix me as soon as he could to stop that pain. He saw a leak in a boat and took the most expedient, and in his mind, most impactful solution.
I think you should consider your feelings, and regardless of if there's any there for him, turn him down. You need a support base, not a boyfriend, and if he rejects you or leaves, then you can say for certain he was preying on your weakness. Learn from my mistake of throwing myself at him because I thought I'd never have another chance and becoming totally emotionally reliant on him for everything.
Also, you should absolutely read darker intentions into this from the start, as
>>102817 says. Doesn't matter if it's true, you should always keep it in mind when you're vulnerable around anyone.