Anguish (συνοχης). Ablative case after εκ (out of). Old word from συνεχω, to hold together. So contraction of heart (Cicero, contractio animi), a spiritual angina pectoris. In N.T. only here and Luke 21:25.

With many tears (δια πολλων δακρυων). He dictated that letter "through tears" (accompanied by tears). Paul was a man of heart. He writes to the Philippians with weeping (κλαιων) over the enemies of the Cross of Christ (Philippians 3:18). He twice mentions his tears in his speech at Miletus (Acts 20:19-31).

But that ye might know the love (αλλα την αγαπην ινα γνωτε). Proleptic position of αγαπην and ingressive second aorist active subjunctive γνωτε, come to know.