Usage of 'Because of' with health/illness

I got two sentences that sound similar and correct in some sense. One of them however should be wrong:

"I accompanied him here because his health was not good at that time."

"I accompanied him here because of his health was not good at that time."

Most sources indicate that because of should be used with a 'ing verb' following it. This source suggests that because of can be used in conjunction with "illness" which to my knowledge is not even a verb. My reasoning for why the second example is correct lies in the fact that "health" is the antonym of "illness" and would act symmetrically.

One reason why example 1 to be correct is that it contains a subject ("his health") and a verb ("was") following because.

Can both these forms be grammatically correct or is one wrong?

Because of needs a noun phrase, as the link you refer to explains. ...Because of his health not being good at the time would be grammatical, but sounds clumsier than your first sentence.