If you accidentally went to this website and you did not spend much time there, then there is no harm on you. You should keep yourself occupied with Istighfaar (asking Allah for forgiveness) and Tasbeeh (Glorifying Allah) and when you remember those scenes try to shift to zikr and Salaah. Allah says in the Quran: Verily those are pious who when an evil thought comes to them from Shaytaan they remember (Allah) and (indeed) they then see (7:201).