When I started retraining my horse last year, I had one lesson where I broke down in tears and was absolutely hysterical. I had to get off and my trainer finished the ride on him. I wasn't mad at him, but at myself because I couldn't figure out what I was doing wrong. I'd lost the communication between myself and my horse because I wasn't asking him to do something right. He was confused and it was my fault. Once my trainer got on him, she was able to walk me through what I needed to do by actually showing me. Then I understood my mistake. I never lose my cool and I never cry. It was just a really bad day. Sometimes you just have to get off and try again another day when you are that frustrated. My horse also had days where he just wasn't mentally in the right place to do what I wanted him to do. On those days, I just asked him for simple work that I knew he could successfully do. You have to be able to recognize this in the horse. Any time you or the horse get flustered, go back to a place of calm for both of you. Even if you just do 20mins of walk work, that's ok, because you finished successfully. Sometimes ou have to discipline the horse to get them back on track, but you must discipline them appropriately. Most importantly, don't stress or freak out. It happens to everyone. You will get to wherever you are going eventually.
Strength is not defined by physical ability. It is determined by your actions and the compassion of your soul.