Kissing custom

In Japan, we do not have the kissing custom. It is still a confusing thing to me.
One day, one of my friends said that close friends kiss on their lips sometimes and I did once and I found out it was not true after that. It was such a shocking event that I could not talk with him for two weeks because of anger. But I would like to do the kissing custom if it is the custom in UK and I like it so I am doing the cheek kissing as much as I can even to the professors and try to get used to it.
Today, one of my professors said to me that in the Uni, students are not supposed to do that to the professors. I think he should have said more early. Already, I did that to many professors. I have a mind to enjoy mistakes and I can just laugh about them but I can not take many mistakes.
Maybe I should do the kissing custom only in the Suffolk. Sometimes my little English brother kisses me on my lips and I am proud of it because it means he really likes me. Love is the thing people can be most proud of, isn’t it?!