There's no such a thing as a special du'a, unless you're think about.. "Allahumma innaka 'afuwon tuhibbu'l afwa fa'fu anni" (means, Allah you are all-forgiving, love to forgive, so forgive me) The prophet (salla Allahu alayhi wa sallam) told Aysha (his wife, may Allah be pleased with her) to say this in Ramadan. But, other than that,I advise you to ask Allah something you understand in your own language, better than reading something you don't understand or won't really feel or mean.
However, I'm worried about "yasin sharif"... there's no such a thing. Qur'an is Qur'an and there's no Hadeeth that says Yasin is special. One Hadeeth was lied on the behalf of the prophet (PBUH). So, be careful! Bid'a is in Jahannam, like the prophet (PBUH) said. May Allah save us and give us shelter from His punishment.
May Allah accept our deeds. Salam...
Qur'an and Sunnah