Speaking from experience of living in a Western, overly-exposed and sexual society, and not being in a postion to get married, here's the advice I can give:
First and foremost, make dua, sincere dua daily (multiple times a day if possible) that Allah (swt) keeps you safe from this sin. Make sure you ask Him to keep your believing brothers safe as well, as I notice when I make dua for others and then myself, they are more likely to be answered, and I believe there are ahadith on this as well.
Secondly, do your best to look away. The moment you see something haram, look away as soon as possible. Try not to register what you just saw as a thought, and completely ignore it. Over time, it will be much easier to look away and ignore these things, but it will be difficult at first.
Thirdly, fast as much as possible. Especially in these holy days of Rajab and Sha'baan where fasting has quite a bit of reward to it, fast as often as you can, at least once or twice a week. (I suggest Mondays and Thursdays, but see what works for you.)
Lastly,do what you can to get married, as these are all temporary solutions. If you cannot get permanently married, perform temporary marraige, there are even websites where you can meet people to do this. If your intentions are pure, and you want to fulfill this desire as a means of staying away from sin, surely Allah (swt) will help you.
Fi aman Allah, and you're in my duas inshaAllah.
Also, always remember, Allah (swt) would not try one with a problem He does not believe the person can handle. So if Allah (swt) believes you can beat this, why don't you?