Is a young man's decision not to marry due to the prevalence of intermingling (ikhtilat), lack of chastity, and distrust in finding a chaste girl considered a deviation from the Sunnah of the Prophet, may Allah bless him and grant him peace?

Marriage is recommended in Sharia, and it is obligatory for anyone who fears falling into the forbidden by abandoning it. So, if you fear committing fornication, then it is obligatory for you to hasten to marry. If you do not fear falling into the forbidden, then there is no sin upon you for abandoning it.

The meaning of the Prophet's (peace be upon him) saying: "Whoever turns away from my Sunnah is not of me," is whoever abandons the Sunnah without believing in it.

It is preferable to marry due to the many benefits it entails, and it is one of the traditions of the messengers. And you must control jealousy within the limits of Sharia.