You can't in any way translate either of those conditions to low SHBG, it's coincidental, that you have the three, but you cannot prove one or both caused you to have low SHBG, and metabolic syndrome is a made up thing anyway that isn't a recognizable medical condition.
Well you just have all the conclusive answers don't you.
Try spending some time on pubmed. There's tons of studies out there that show how low shbg is HIGHLY associated with insulin resistance, fatty liver, dyslipidemia, and metabolic syndrome.
Of course I can't "prove one or both caused me to have low SHBG" just like you can't prove it didn't.
SHBG is mainly produced in the liver. All of those diseases are liver related. There seems to be a strong correlation there.
Like I said, it seems some people just have naturally low Shbg.