Foreskin Related

Thank's for sending that reply. That thing i am practicing since last 7-8 days. My penis foreskin goes back behind the glans. But when the penice starts erecting it becomes very tight and there is a lot of pain. Is this pain natural? Will the foreskin opening of my penis become loose? Also plz tell me that when i have sex then should i pull back my foreskin and then insert my penis into my girlfriend's vagina or as it is in erection state? I also want to ask u that ejaculating every day is safe or are ther ay side effects of it? if a regularly keep touching the glans of my penis then will the pain vanish or it will only go by having sex?