Also what have you done to mitigate the existing attack?
Wiped the drives. New Os (which will probably be wiped again for Linux). Changed a lot of passwords. Did some meditation to clear my mind. Drank a lot of coffee.
I recommend you buy a good anti virus like Norton or Kaspersky. IMO linux is an overkill if you haven't used it before. It's a bit more secure but you sacrifice some of the looks of windows and its compatibility with different programs and games. I also find windows much easier to use, more user-friendly. Ultimately it comes down to your cyber hygiene, not the OS that you're using. If you download infected files from the web, click on phishing links and carry data from other computers on USB drives, you will get data breaches sooner or later, regardless of what OS you decide to use.
I assume you know all these things, but haven't turned them into habits yet. As cruel as it may sound, being hacked is a great wake up call. My friend got all his data encrypted by malware and that was his time to start being more careful. Most people don't use any security until they get shit stolen.
I do not want to offend you, but if you do not understand something, it does not mean at all that it is superfluous. Given what people advise the OP, it is the absence of various programs and games that is desirable for a computer that conducts financial activities. Other than that, you won't believe how beautiful and convenient Linux can be, unlike Windows. It also has graphics to create a pleasant interface, although most of its users hardly need them.