Problems with the body

Hello, friends! I'm Dante, I'm from Russia and I'm 17 years old. Immediately I apologize for my level of English, I am very bad at this language. So, until one day everything was fine, but the next day my girlfriend came to see me. And I realized that something was wrong with me, my penis rose only during passionate kisses, stood for a few seconds and fell again. This cycle was repeated and repeated. I started to worry a lot, I read all the Russian-language sites, many people say that this is a porn addiction and you need to give up Masturbation and watching porn for a while. Also, some people say that this could have happened due to a violation of sleep and nutrition (I slept for 5-6 hours a day). The penis is worth it, but it is very weak and time is short. Brothers, tell me, please, will all these tips help me, about the regime and a break from pornography?