It is one goal of the GMAT to get you unfocused so that you pick wrong answers.
It probably takes you 1.5 hours to finish your daily test, but on a mock test you have at least 75minutes of Q before you start V (if you skip AWA).
Try to focus on your daily preparation for 2.5hours. I know, it is not always possible due to lack of free time, but it is important to get your brain trained to focus again for more than 1h. Use the time on the weekends. I normally do 2.5hours in the morning, have breakfast and do some sport (1.5h) before starting one mock test (without AWA). Next day is completly blocked with reviewing and reading strategies again.
If your fundamentals are strong and you do mostly mistakes due to lack of concentration, you can only force yourself to read uninteresting articles and answer questions even though you do not want. Eat healthy, do sport, and drink water instead of coffee/energy drinks. Practice, Practice, and Practice