Has anyone else found professional certification exams harder than expected?

I decided to pursue the PMP certification because I thought it would help me move forward in my career. What I did not expect was how difficult it would be to balance exam preparation with a full time job and everyday responsibilities. Most evenings I sit down to study but I am already mentally exhausted from work. Last night I completed a mock test and my score was much lower than I hoped. I felt discouraged and started thinking that I might need a PMP exam help service to better understand the areas where I keep making mistakes. Has anyone else gone through this and found a way to improve their confidence before exam day?