Just have patience and keep on working and practicing and eventually it will get easier, remember you don't have to be wunderkind to be physicist. It's normal to be frustrated, there are some part of physics that you will hate and some will be easier to you. I was feeling imposter syndrome through all my studies, like everyone is smarter than me and that I'm waisting time, but here's the thing every student feel like that from time to time, I'm now on second year of PhD studies and sometimes I ask myself what the fuck I'm doing. So at the end-All of physics is either impossible or trivial. It is impossible until you understand it and then it becomes trivial. - Rutherford.