I'm sorry but 6 months is about 6cm or 3 inches worth of growth and it seems to me you got for sure 2 inches. 1/2 is "average" growth, meaning that for some it grows faster, or even slower. But it seems right about on track to me.
ETA: hair growing is a patience test for sure!
I would not trim, trimming makes it even worse, so I just would continue to grow, and you are almost waist anyhow, so almost something to celebrate! I'd be positive about that, at least!
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