Yes it relaxing an fun
Moderate masturbation, say once or twice a day, will not harm you physically, and is probably good for you emotionally. More than that might be problematic in terms of a developing compulsion.
Yes it is.Allah says in the Surat al-Noor, Ayah30:قُل لِّلْمُؤْمِنِينَ يَغُضُّوا مِنْ أَبْصَارِهِمْ وَيَحْفَظُوا فُرُوجَهُمْ ۚIt would be translated as:Tell the believing men to lower their gaze and guard their private parts.
There is a difference of opinion among Islamic scholars on this topic. Some consider masturbation to be haram (forbidden), while others believe it may be permissible under certain circumstances or conditions. It is recommended to seek guidance from a knowledgeable religious scholar to understand the specifics of this issue in Islam.
Don't worry. This is only a problem if it keeps you from having a social life -- doing things with other people. Almost all of us masturbate. I'm in my sixties and I still do it.