Cyberstalker somehow keeps tracking my PC or internet activities

Hello, I need some serious help dealing with a potential hacker who’s been cyberstalking me online for the past 3 or 4 years. This individual is extremely obsessed with me, I met her from an online video game 4 years ago, and after I quit that video game, is when it started to get extreme. This individual managed to find multiple of my social media accounts, forums to forums, sites to sites, and especially reddit. I’ve made multiple reddit accounts, and she found every single one of it somehow, I’ve tried rando name generator as nickname, I’ve tried posting to a different and random subreddit, I’ve tried changing writing styles, nothing would be able to link these accounts together, except if the individual is literally in my PC or network, listening to every activities. It’s making me feel quite paranoid, so I took some measures against it, but to no avail. I installed multiple antivirus antimalware antispyware, everything possible, and it did absolutely nothing, so I resorted to the last option, nuke the PC, clean install, wiped disk, zerofilled, format, completely brand new, and of course, does not help. I’m starting to at this point suspect it’s network related, so if anybody is an expert in this, I’d be very appreciative of any advice and help. I tried checking for unusual devices in the network, and nothing was out of the ordinary, though it showed there were 200+ unknown and inactive.

Also, I know one of this individual’s Twitter, and I don’t know if it’s a coincidence, but at the same day that I decided to visit a particular website, this individual decided to talk about it on her twitter. On july 26th, I visited a popular website around 2-6 pm, then this individual made posts talking and discussing topics related to that website at 11 pm on their twitter, it literally seems like this individual is spying on my PC or network. I contacted one of the stalker’s online friends on discord in seek for help, and her friend told me that she’s a psycho, comp sci major and is really good with computers, so that further confirm things.

Do not double post on the forum