Norwood Hamilton is always an approximation, but you had general thinning at the highest grade.
There also looks to be a beginning of a separation of an "island" in front that if you had let it continue would have given you "two" hairlines. You definately have mpb, and you have DEFINATELY made the only safe choice other than let it continue. It's tough, but you're going to get in front of this, the beard will develop and you're going to be fine. BTW, your dome looks great.