Yes, the GMAT is tough. You should expect to spend about 4 hours at the test center. The GMAT will feel hard for everyone who takes it. The reason it’s going to feel hard for everyone who takes it, is that it’s an adaptive exam. So, the Math section and the verbal section of the GMAT adapts your performance. As, the GMAT is on a computer, so what happens in the math section of the GMAT, the more questions you are answering correctly- the harder the exam starts to get. The computer will start giving you harder questions. The more questions you answer incorrectly- the easier the questions start to become. The same thing happens in the verbal section.
So, the GMAT will feel hard for anyone who takes it.