Your job isn't your life. The problems with the code aren't your personal problems. It can definitely feel like it at times, but they just aren't. You'll move

Your job isn't your life. The problems with the code aren't your personal problems. It can definitely feel like it at times, but they just aren't. You'll move on from that code. Probably to some other code that is also fresh hell. Doing a good job in our industry is hard. Doing a great job in our industry is neigh on impossible. Take it one day at a time. I worked on a product for 5 years and couldn't tell you all the moving parts. I'm now 3 months in to a new job and the complexity of the software I'm working on is absolutely overwhelming, but you start small and work towards the bigger problems.