A topic sentence should be a general kind of "preview" of the paragraph. Keep it simple, make it really, really clear what your paragraph will be about.
For example,
Donne’s use of techniques enables us to vividly understand the aspects of life and experience inherent in ‘Batter my Heart’. The form of the poem is crucial in establishing Donne’s tone. The structure of the poem can be differentiated into 1 octave (2 quatrains) and a 6 line subset (1 quatrain and a couplet). This division is representative of the tone of poem. At line 9 a conventional Elizabethan Volta occurs. The tone changes from suicidal and pessimistic to intimate and hopeful. Donne at first is very cynical and depressed, struggling to come terms with sin. He is convinced that this sinfulness has made his soul so impure God will not accept his spirit into his kingdom of heaven. However by Line 9 Donne becomes more personal – expressing his undying love for God. Donne’s final request is for God to take him as his prisoner, believing this is the only way to attain true freedom.
In the paragraph above, it is made clear that the paragraph will be about how techniques are used to understand aspects of life and experience in the poem. Then the paragraph elaborates upon the form of the poem communicating that the composer has used deliberate structural techniques to collect, order and clearly express his inner thoughts.
Hope that didn't confuse you too much. The last piece of advice I suggest to you is to keep it simple. Simple is better. Less is more. It sounds like you are a smart kid with excellent analysis of texts. The opening of the paragraph enables you label, collect and 'brand' all those good ideas of the paragraph and express them in a succinct, concise and easy to understand sentence.