I went to the library.

This morning I went to the library, because the midterm exam has left only a week left. Though it's sunday, there were many people there in the library. I ate lunch and dinner at the restaurant in the library, because the library is near my house and the food from this restaurant is delicious (I switched these two sentences around because it follows a better train-of-thought that way ;). I had ate lunch alone, but I ate dinner with my parents, and after dinner, my parents went back home.
I wanted to go back home with them, but there were are many things I had have to study.
So now I'm in the library, and still there are many people in here.
I hope the exam is over quickly.

All the highlighted things are corrections I have made =D I hope it helps you. Your English is very good! Please ask if you have any other questions for me!