2fa was just email which does not appear to have been breached, but who knows.
I did just find a keylogger on the PC.
MSDCSC.EXE installed 11/19. that is also the same day as a wallet file mysteriously showed up.
Sorry about your lost.
I recomend you to use Linux, i use linux and i know my bitcoins are safe this way. i will never found a trojan or a keylogger on my computer, i recomend you to give a chance to linux.
You can keep tracing the transactions, maybe that whay you will find who did it.
Good luck.