Thank you everyone for helping out!
I took Cherie's advice today and got really confident and assertive. Every time she got insecure and started speeding up the walk, I pushed her faster instead of shrinking down and trying to slow/stop her. For the first few moments of pushing her faster, our energies would sort of "clash", if that makes sense, but after a minute, she would settle down. This is a large difference than me shrinking and trying to be quiet and relaxed, and her being insecure the entire time and never settling down. I found that if I want her to relax after she's started going into insecurity mode, my "energy" needs to be stronger and more vibrant than hers, sort of challenging hers. I don't want to go all "new age" on you with this talk of energy, but that's the best word I can find to describe what it felt like.
Today I never let her look at or pay attention to what was scary or interesting (unless of course, it was me who was scary and interesting
). The best example all day was an encounter with fire. There's a lane that runs by my neighbour's house that takes you to most of the trail paths, and my neighbour had lit a fire to burn garbage or something. The first time past, my horse bulged right out to try and get away from it. I went on a little ways then looped back and passed it again, and continued this 4-5 times. The last time, she barely bulged at all and nor did she look at it-she had one ear on me and one on the fire, but continued straight on.
By the end of the ride, all I had to do was bump my leg or fiddle with one rein and at least one ear would flick back to me. I did not go very far from home today, but at least I feel better about controlling her now, and know that I CAN control her.