Just memorize them by rote. There's nothing actually connecting them via spelling; they're completely different words with completely different backgrounds and that's a thing you have to get used to in English.
Remember English is a creole of a bunch of different languages and that's why it is the way it is. It doesn't really have rules like that aside from some basic grammar.
Well, you can sit and hate all you want, the rest of us will have fun with or without you.
The only one who's going to suffer from being so miserable is you.