Malbyte anti-malware

So, I have this disney plus account. And ever since its creation it has changed hands from me. Back to another email that I will not mention. Every time I contact support I provide a verizon # to verify the account should belong to me. Then my email is restored. After a random amount of time, I will find it is back to the other email. I know my account is not being hacked. Before I was unsure, but this time I am more certain. I am more certain because I ran several virus scanners, AVG, Malware Anti Malbytes Pro, Windows Defender, ASC, Norton 360 (I dislike this one but I digress), Kapersky and bitdefender. All pro which cost an arm and a leg.
After all of that was done securing my PC to obnoxious levels, I finally changed my email password, then again changed my PW to Disneyplus. Since that day. I have not logged onto Disney plus on any device, nor have I visited the site. But still today, I found it changed again. Support was nice enough, but was unable to do anything other than change it back... again. I have no clue how to get this fixed, and it seems. Neither do they.
I wanted to start from square 1 but I have the verizon deal where its free. So they won't let me start from scratch. Just change my email.
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Has anyone else experienced anything like this?

So I checked my email just now and noticed I had four emails from Blizzard. 2x "Account verification" and 2x "Security check"
I dont remember any logins today or yesterday (They were emails on the 25th, it's now 1:09 Am on the 26th.) on my laptop or my desktop.
I did start up my laptop earlier tonight to watch a few movies with family but I also have done that yesterday (24th) and I dont have any emails from Blizzard from that day.
I cannot quite say when the emails arrived as Hotmail/Outlook doesnt show a timestamp anymore besides the date.
I've already ran a full test with Malbytes Anti-Malware, Superantispyware and Windows defender on W8. Superantispyware removed a few tracking cookies but as far as I know they're mostly harmless and were removed. The other two came out clean.
I've got no requests to change passwords or anything on things like Steam and everything seems to be in working order.
I'm not sure if I'm just spooked or if my PC/Laptop is infected. If something IS on my computer I dont think it's a good idea to change my passwords yet. Any ideas?
Edit : now following the Official Malware removal guide

I have a custom built PC, using Windows 7. I've been using a trackball mouse for a couple years on it no problem. A couple days ago while I was browsing the web, my mouse started moving on its own and constantly selecting things on my desktop. My files were opening and more than once the administration access window popped up (I browse on an account that requires admin password for anything majour, for added security) so I shut down my computer. I did this through the start button, I managed to wrestle the mouse over to it. Now, every time I connect to the internet, my mouse starts right and left clicking constantly. The clicking starts if I leave the mouse motionless for at least half an hour.
I've disconnected my internet and ran a full scan with both my antivirus (Kaspersky) and my anti-malware program (the free Malbytes one). Malbytes didn't find anything concerning, nor did my antivirus. The only recent security risk I can think of is that I downloaded the newest version of the vanilla minecraft server from their official website, but I can't help but doubt it is the culprit.
I've reset the computer, disconnected the mouse, double checked that 'remote assistance' is off/not allowed. I've also cleaned my mouse and the trackball (Which I do regularily anyways). I've pretty much exausted the limits of my computer knowledge. Any suggestions?
Also, sorry if my formatting's off. I'm not used to using my phone on Reddit.
Edit: Forgot to say this, sorry. But it seems to happen after 1am, so I'll be trying those suggestions then. Thanks for the replies so far! Any help's appreciated.

Hey guys, I'm posting this since my chrome search bar has been getting hijacked by what I think to be some sort of strange malware for the past couple of weeks. Here is a picture. Does anyone have any tips for getting rid of this? I have scanned with windows defender, malbytes anti malware ect. This happens after I type something into the search bar at the top with it set on google, it takes a couple seconds to load and says redirecting. Sometimes even when I use the google search engine, it hijacks it to yahoo.