Hello, I hope all of you are doing well.

I've been live streaming to YouTube for around a year already. In this time, I've had plenty of fun, played some great games and have met some great people. However, I have a troll problem. For the sake of anonymity, I won't be using this user's actual username.

I've had to deal with this troll and his friends as I've been cursed with this individual having a vendetta towards me. I've been hit with sexual remarks towards my viewers, have had this individual along with his friends make me have 0 progress in a Crowd Control game, and this individual has also tried everything in their power to take down my channel and is honestly just a huge hassle to deal with. I first encountered this individual through Twitch (I multi-stream), but has since changed over to YouTube.

I've tried everything from being overly aggressive towards them to try and get them off my back, to trying to ignore them (this still increases my stress levels as I still see the messages). And of course, since I'm fairly small I respond to most of my viewers when they're discussing something that I can add my own thoughts and voice towards. The troll notices this and accuses me of ignoring them, which I do because I'm trying to get them off my channel.

I've also tried banning them, but due to their ability to create multiple new usernames and alt accounts, this gets very tiring very quickly. I also have heard reports that this troll individual has reached out to other viewers in an attempt to get to me or harass my other viewers and mods.
Has anyone dealt with a similar situation? Is there anything that I can do to permanently block this person's IP address or something similar? Thanks for any and all replies. I'm going to try to reach out to both Twitch and YouTube directly in regards to this as it has wrecked my love of streaming and I'm currently on a break as my mental health has deteriorated over this and other personal issues.