Why can´t I think straight? I got lots of sleep.

Sleepdeprivation. Although sleep deprivation can cause cognitive problems other causes need to be looked into. Check with your physician for adequate assessment.
Slow down and focus. I'm glad you get lots of sleep and i hope that you also exercise regularly, eat healthily, and keep yourself well-hydrated. Your difficulty "thinking straight" might have to do with ever-present low-level anxiety or with having so many things on your mind and so many distractions in your life that you feel overwhelmed and flooded. Meditation and mindfulness exercises might really help. Good luck.