There is a fundamental difference between the English labels "transitive" / "intransitive" and the Japanese labels 他動詞【たどうし】 / 自動詞【じどうし】. Please read the thread about that here:
Can verbs be both transitive and intransitive?
Key point: 自動詞【じどうし】 can sometimes have a syntactic (based on the grammatical structure of the ...
殺され is passive. As has been so kindly pointed out in the comments, the sentence reads, "I came to be killed by you".
For a moment though, let's look at a slightly simpler sentence:
This sentence reads "I was killed by you".
In a passive sentence, the agent, the one who's actually doing something, is marked by に。
In order ...