All I can say is I'm glad you're addressing this now. I am hiring a trainer to do private sessions to deal with the same thing with my dog, but he's 4 and this has been going on for awhile (bad me).
If I learn anything new and different, I'll be sure to pass it along. I know a lot of people swear by crate games, controlled unleashed, etc....but for myself, I need more than a 4 hour class, or things that deal mainly with crates. We have to move beyond that and somewhat fast (well, I need to learn one thing, apply it, etc so that's slow, but by fast, I mean, we need to fix this now).
Good luck. It seems like you've been doing a lot of great things. I will say this though....after watching a lot of herding breeds in agility, not all dogs can be cured of their reactivity, but you can teach them how to deal with it.
Oh...this one woman I know. Her dog always has a toy in her mouth. When she gets excited, she lies down and kills the toy. No barking, no running after anyone, etc. I am impressed. I'd love to have that. I'm not forcing my dog to be calm, I'm just teaching them to do something else when they're reactive.
ETA. I don't want to scare you into not using a head halter (gentle leader). But just be careful. Also, a lot of people (myself included) link the leash to the head halter and a regular collar. When I first started using a collar (not harness), Koji would run and get whipped around when he'd hit the end of the lead. The first time I put the gentle leader on (head halter), I was so scared he'd do that and break his neck. Well, for a bit, he didn't. I think he disliked it enough that he was calm. But, once he got used to it, yup, even when linked to a regular collar also, he whipped himself before I could stop him. I quit using it for a long time after. I have only begun to use it again, now that he responds to me better. Just be careful and keep an eagle eye on Precious (so that she doesn't take off like Koji did, trying to chase a car down and get whiplash from the lead). Koji is the type that catching the moving object is WAY more important than a lead, gentle leader, collar, harness, me, food, etc. So, in that, he becomes dangerous on a gentle leader. Sigh. HOpefully I'll get some great training soon.