Imagination is part of human behaviour which is quite common, but deciding on what you are imagining and fantasising is under your control. Are you building castle in Spain, are you imagining being with someone and then mastrubating etc is what you need to consider.  Using pen etc can really be harmful in case of any internal injuries. Indulge in some productive tasks that helps you in your studies, career and future. Exercising, sporting, gym etc will be helpful.  Daydreaming of receiving awards is not wrong. Why not excel in some productive stuff such as sports, music etc and you too are capable of receiving awards. Work on setting life goals and move ahead. Deviate your mind to something else when you feel the urge of watching porn, otherwise in long run you will have challenges. Probably you will not enjoy sex in your married life as you feel satisfied watching porn.  You are just 19 years old,  refrain from addiction and lead normal human life. Life is really beautiful but the key of happiness is with you.