Complex sentence: Haydn's original title may also have come from illness and exhaustion at this time following the supervision of the first performances of The Creation, completed a few months earlier, or even from the challenge of composing without the desired instrumentation.
Split into simpler sentences: Haydn's original title may also have come from illness and exhaustion at this time, which followed his supervision of the first performances of The Creation, completed a few months earlier. More simply, it may have sprung from the challenge of composing without the desired instrumentation.