Sentence examples for so frustrating from inspiring English sources

"so frustrating" is a grammatically correct phrase and can be used in written English.
It is often used to express a strong feeling of annoyance or exasperation. Here are some examples: 1. The long wait for the train was so frustrating, especially since I was already running late. 2. I just can't figure out this math problem, it's so frustrating! 3. It's so frustrating when people don't follow simple instructions. 4. I spent hours on this project and it still doesn't work, it's so frustrating. 5. Dealing with this company's customer service is always so frustrating.