However

Could you teachers please kindly verify my sentences? Thanks in advance.

1) Many people believed that John was wrong; I, however, had the opposite view.

2) Lots of people said that I would not be able to pass the exam. At last, however, I was able to obtain the highest score amongst everyone else.

3) Lots of people said that I would not be able to pass the exam. At last, I, however, was able to obtain the highest score amongst everyone else.

4) It was proverbial that he was the most humourous person in the school. He, however, denied that in an in-school television interview.

5) It was proverbial that he was the most humourous person in the school. He denied, however, that in an in-school television interview.

6) I love her very much; however, she does not love me, not even a bit.

7) I love her very much; she, however, does not love me, not even a bit.

8) I will achieve the highest mark I can however hard it is.