Doctor, I have plenty of bump locate at end of shaft (left, right, bottom) but no the upper skin, negative herpes2, so what is that? No pain/itchy

Many possibilities. There are many things that could cause the skin to itch. Several types of inflammatory conditions of the skin, allergic reactions, and sometimes bacterial, viral or fungal infections can cause rashes on the skin. Insect bites can also be the cause of a rash on the skin. Have it evaluated by a professional and get the appropriate treatment.