Quelqu'un peut-il me dire ce qui se passe avec mon gland ? Est-ce une balanite ou quelque chose de plus grave ???

You do have some level of irritation to the skin on the head of your penis - so yes. this could be termed balanitis, which I find is not a particularly helpful term.
What you need to think about is what has caused this and that would determine what is required to treat what is going on.
So, have you recently had unprotected penetrative sex or received oral without protection … ?