It is all about learning to recognize your point if no return and stop ALL stimulation at that point. It has nothing to do with porn and it can be fixed. Here is an article I wrote on it last year: https://www.linkedin.com/pulse/article/three-ways-fix-your-premature-ejaculation-rynne-online-doctor/edit
First quit porno watching.Then try to reduce masturbation. Yes it is difficult to bread this habit. You can take help of special breathing to break this addiction. The breathing is called abdominal breathing.(google). There is no need to completely stop masturbation but reduce it as much as possible. Do abdominal breathing for 10 minutes twice a day. and use this breathing to calm your sexual urge. 6 or 7 breaths will calm you completely if you practice it regularly.If sexual urge is extreme, you can masturbate with the following tips; Use lubricated hand,do not stop breathing, do no do it in prone position, be on your back. empty your bladder before masturbation. Be patient. masturbation does not harm is you do properly and in limit. Do not worry about masturbation. worrying harms more than the act.