salamualeykum, all the ways that someone can hold his lust if he fasts, tries to seek knoledge stay away from places and cant move countries nor marry, anytime he goes to the gym or outside the fitnah hits like a truck no matter what, and he tries to lower his gaze but the first glance hits.

Ustadh AbdulAziz al-Haqqan

Then avoid these places of fitna. If it is a mixed gym, it is not allowed for you to go there. For going out, go to places where there isn't fitna and minimize the number of times you go out in order to protect yourself from the fitan, as you have said you are suffering from them.