！！
You're the worst — not just as a man, but as a human being!!
Literal
You [topic-は] man [as-として] [quotative-ってゆうか] human [as-として] worst [copula-だ~]!!
ってゆうか is the casual pronunciation of というか 'or rather / I mean,' used to escalate the insult from 'as a man' to 'as a human being.' 最低 'the worst / the lowest' is the superlative of 低い and the go-to insult for moral condemnation. だ~ with the elongated tilde adds dramatic fury. A quintessential anime/drama breakup line.