Left Click Problem

Been having this problem since 1.13, and didn't expect it'd go on for this long.

Like most people, I use left control as my sprinting key, and now as I hold it, my left click registers as a right click. Also, I used to use my function (fn key) as my sprint key, but for some reason that was taken out in 1.13 as well. That key worked best for me as its in the bottom left corner, kind of how for windows pcs, control is directly in the bottom left corner.

Can someone add the fn key back to the controls for mac or at least fix the left control sprint and click problem? (preferably both)