I finally got my horses to my house after over a year of working on a barn and pasture for them. When I brought them out of the pasture at the barn where I boarded them on Tuesday, my horse scared the absolute crap out of me. I have never been scared of my horse ever. He would NOT listen. He was trying to run ahead, was bumping into me, neighing, and even rearing! I was so scared that I let him go. After I composed myself, I went back and got him. My mom had her horse already and so I yelled for her to wait for me. Tanner walked just fine all the way to the barn! So fast forward to yesterday and today. I have my horse in his stall and my mom has her horse in his stall right next to Tanner's. Tanner can see Flashy through the bars. Well, my mom let Flashy go and Tanner went crazy!! He started pulling on the bungey that he was attached to and acting like a nervous wreck. He neighed and Flashy came over, as to reassure him. Now Tanner has NEVER acted like this in the 12 years I have owned him. He obviously has some serious separation anxiety from Flashy. Flashy is the dominant one and Tanner follows Flashy all over the field. When we boarded them, they never acted like this until I put him in the pasture at that barn 8 months prior. Since then, I hadn't really gone to work with him because of working on the barn here for them. I went and visited, but never took him away from the herd. What would cause this separation anxiety? And my biggest question is how can I help him get over it? I'm sort of afraid to ride him if he's going to rear and carry on just from being away from Flashy. It's so crazy!! I've even sort of afraid to even walk him away from Flashy since he almost trampled me last week. :( I feel like such a loser because I'm a tad afraid of my horse. I've worked with horses since I was 9, so I just feel like a failure that this has happened. When Flashy is in the stall next to him, I can groom him and do whatever with no problems. But the second he leaves, he flips out. Any advice y'all can give would be great. Thanks in advance.