How can one get rid of the feelings of guilt and anxiety resulting from having previously directed people to watch TV series or listen to songs, and is it necessary to contact them to ask for forgiveness or to advise them?

If a Muslim is sincere in their repentance and regrets what they have done, and strives to advise those they led astray and invites them to Allah, then they have fulfilled their obligation. After that, their persistence in the path of deviation will not harm the Muslim. Scholars have stated that whoever repents from a sin, their repentance is accepted, and the lingering effect of their sin does not harm them, like someone who spread an innovation (bid'ah) and then repented from it. Sincere repentance erases what came before it, and "the one who repents from sin is like one who committed no sin."