frustra: often of a finally unproductive investment; nequiquam, of one hopeless from the very beginning.
credite: believed; cf. Verg. A. 11.247 “[Cassandra] non unquam credita Teucris” .
[2] With the rhetorical figure (epanorthosis) in frustra … frustra? immo, etc., cf. Cic. Catil. 1.1.2 “hic tamen vivit. vivit? immo” , etc.
[2] magno cum pretio: cf. Catul. 40.8 “cum longa poena” .
[4] hei misero: cf. Catul. 68.92ff.
[4] omnia nostra bona: i. e. Lasbia's love; cf. Catul. 68.158 “omnia bona” ; nostra is for mea, with a change from the singular personal pronoun in the preceding verse like that in Catul. 91.1f; Catul. 116.5f.
[6] nostrae: i. e. the mutual friendship of Catullus and Rufus. With the change from the singular meaning in the preceding verse cf. Catul. 68.94ff.