Du ließt mich immer so bang
is a malformed sentence. What tense is it supposed to be?
Present tense: Du lässt mich etc.
Past tense: Du ließest mich etc.
Second, you can’t use bang like that. In contrast, here are a few uses of bang (or the verb, bangen) that would not sound un-idiomatic:
Du lässt/ließest mich immer so bang zurück
Du lässt/ließest mich immer so sehr bangen
but they carry different meanings. In any case your two sentences do not fit together. In the first, the speaker is happy, in the second he is anxious. Why the sudden change?
But don’t feel bad about this, Tom. Even as great a poet as Nobel prize-winning Joseph Brodsky struggled to express himself when writing in a second language:
In contrast to other exiled writers who lock themselves up inside
their mother tongue so as to protect their creativity, Brodsky delved
headlong into the enticements of his second language (…) The results
are sometimes words, or juxtapositions of words, that test the limits
of poetic license. This is the vague criterion that has made some of
us wrinkle our brows: when does the foreign poet, writing in English,
trespass boundaries of legitimate linguistic inventiveness? For which
lines, for which exact words, should Brodsky perhaps have heeded the
(presumable) doubts of his co-translators or first Anglophone readers?
In May 24, 1980, translated by the author, Brodsky seemingly recalls
his open-heart surgery: “Twice have drowned, thrice let knives rake my
nitty-gritty.” Note the proximity of the literary “thrice” and the
slang “nitty-gritty.” Note the knives that “rake.” Note the way
“nitty-gritty” has become, in Brodsky’s mind, a synonym of, say,
“guts.” Of course, the poet is making a philosophical point:
“nitty-gritty,” in the meaning the term takes on in the expression
“getting down to the nitty-gritty,” posits the body—in general,
matter—as the ultimate horizon or dead-end of existence. In any event,
Brodsky’s mature poetry, whether written directly in English, or
translated by himself from Russian originals, sometimes raises these
stylistic and lexical questions. At times the questions become
barriers, however slight or surmountable, to a full appreciation of a
poem. Source
In case it isn’t immediately clear, the message the author of that review is trying to cloak in politeness is this: often when writing poetry in English, Brodsky sucked. Think of that as a cautionary tale …