If you are going to Sweden, physical currency usage is very low there, I've spent a few months without using any physical currency with no issues at all.
Few things,
- Do not try to buy SEK here, it's really a waste of money with exchange rates. If you really want, bring USD, you can exchange it at a fair rate there (I have done this). Do not bring EURO, you will have to pay a considerably higher fee than for USD
- Enable usage of debit/ credit cards there, the rate is good now (earlier it went up to ~36 now its ~29)
- Use a Wise card, it has many benefits, and the currency rate there is the really good
talk to me if you need more info or help