Is ghusl obligatory for me when practicing masturbation if semen does not come out at all?

Masturbation is forbidden, and repentance from it is obligatory. Ghusl (ritual bath) is not required unless semen is discharged. If nothing is discharged, then nothing is required. If pre-seminal fluid (madhi) is discharged, then wudu (ablution) is required. If the well-known semen is discharged, then ghusl is required. Without the discharge of semen, ghusl is undoubtedly not required.