Keep it, the vast majority of games for the switch, dont really require multiplayer to enjoy.
Just play all those games you "won" when you bought that switch and enjoy them.

I'm a bit of a stickler/weirdo? for not having any interest in jailbroken systems, to the point I would immediately delete all that stuff. I like it legit. But hey, congrats.

1 you should not feel guilty
2 you paid for a switch so you have not stolen anything hence you should enjoy what you purchased hacked or not
3 do not take that system online until you have completed all the games and if you don't want to play them simply sell the system on eBay they will pay you a great amount for a hack system but remember to mention that you got it at a pawn shop so you aren't blamed for the hacking of that thing

a) If you dont play online that often, keep it for sure, and play the games. No shame.

b) If you want to play online, than reset to factory settings and start with a brand new account just in case. You still got a free 200gb sd card which is pretty neat.

c) Keep the SD card, (and the game in the cartridge slot if there is one), and either return or sell that switch, buy a new, non hacked one.

Jesus how much did you pay for it and where can I get mine?