Your English is fine.
I used to think porn was not harmful. I even convinced myself it could be helpful.
But even setting aside exploitation, and focusing just on the consumer ... it is like other drugs. Some people can get by with occasional use -- but when it becomes a habit, and the habit starts demanding more time, longer sessions, more and more deviance ... there is an issue. And it's not good.
Porn is a hyper-stimulus that, over time, will fry the very circuitry in your brain that causes your body to become aroused. You will become dysfunctional. And it can get worse ... it can go beyond sexuality and wreak havoc on other responses, relations to other humans (and this is the WORST ... it's worse than PIED) . We were not designed to be exposed to this kind of easy access to intense and almost infinite variations for as long as we can click a mouse button. There are certain psycho and psycho-physiological realities that we are constrained by and we had better respect them.
If you think you have a problem, you almost surely do. Come here. Read peoples' stories. Know you are not alone. Know that you have people to talk to.
And make it your top priority to get OUT of this habit. I mean, completely out. Ask for help and suggestions.
There is LOTS of help here and elsewhere as well. Look up porn addiction on YouTube. There are also other websites. I find this website very supportive.
Welcome, and may you do well.