The only reason you think there is (or was) an epidemic of police shootings of unarmed Black people [...]

This is unfair - note that the comment you are referring to didn't specially mention police unarmed shootings of blacks, the comment was about disportionate policing and killings (which presumably includes, but is not exclusive to shootings of unarmed citizens). I mention this because police shootings are not the only manifestation of institutional racism. There are also unjust arrests, accusations, beatings (remember, Rodney King wasn't shot), convictions, and general mistreatment. You might beat the rap, but you won't beat the ride.

As a relatively well-off, straight-laced black man, I'm not overly afraid of getting shot by police (although I think I got close to catching a bullet once), but I am terrified of a stop going bad in some way, not because of what I observed in the media, but because of my own personal experiences.

I live in a high-crime city in the northeast and as big component of my job is spending time in high-crime parts of cities all over the US (most recently, Chicago South Side, including Altgeld-Murray projects). The only times in my life where I thought my life or safety was in serious jeopardy involved interactions with police.

Furthermore, Black communities are often strong advocates of retaining or even increasing police presence

Absolutely true, and that reflects my feelings as well. But that is not the same as saying black communities trust police.