Please understand that I can't be of much help.

Literal

Strength [object-を] lend [nominalizer-こと-は], hardly cannot [quotative-と] think [please-てください].

力を貸す ('to lend a hand, help') is a set phrase. ~と思ってください is a polite way to soften a statement — 'please think of it as X.' ほとんど~ない gives 'hardly,' modulating the negative. A humble apology-style sentence.