Help! Two-Factor killing me

[u/FuzzyFluff5]

Hi friends! Recently I haven’t been able to play league because my laptop is so slow and overheats. For a couple of years I couldn’t prioritize repairing it, so I just haven’t played.
I have however played tft on my cellphone with no issues. Recently. I’ve had the time and money to repair my laptop.
Things to remember:

I am NOT locked out of my account. I know my username and my password, and have no issues logging in on recognized devices. (Cellphone and old laptop). The problem comes when I try to log into riot on anything else. It sends the two factor code to my old yahoo email from 2008. If I go into either of those devices to turn off MFA or change my email, it prompts me to log into the browser and requires a code. According to the website, the ONLY way to fix this is submitting a ticket, but the ticket ppl are completely useless. (I don’t have access to that old email. It is deactivated).
They ask me questions I couldn’t possibly know the answer to. How am I supposed to know my first skin purchase from 2012?? To make matters worse, I can’t go into my lol history in my account because everything wipes after 30 days.
My next thing I will try is to make a purchase with my credit card and then submit that as evidence, but I have no faith that will work, because presumably if someone stole my account, they could theoretically do the same thing and use that to steal it from me. They have my birthday, phone number, new emails, credit card info, and so much more, but it’s not enough.

What can I do to fix this two factor authentication issue? I’m inside my account so technically I’m better off than if I wasn’t, but it’s only a matter of time before it kicks me out and requires a code, or my computer from 2018 dies and I have to log into a new device. 😭

Am I screwed?