Wherewith (hēi). Either locative case with preceding en or instrumental of the relative with pareklēthē (first aorist passive indicative). “The manner in which Paul, so to speak, fondles this word (parakaleō) is most beautiful” (Vincent).
In you (Ephesians' humin). Over you, upon you.
Your longing (tēn humōn epipothēsin). Late word from epipotheō (epi, directive, longing towards, yearning). Only here in N.T.
Mourning (odurmon). Old word from oduromai, to lament. Only here in N.T.
So that I rejoiced yet more (hōste me mallon charēnai). Result expressed by hōste and the second aorist passive infinitive of chairō with accusative of general reference.