It is not a "problem" by itself, it just takes very long time to validate each block on the blockchain. If you use a SSD instead of a HDD it will take less than one day in total. Also, once version 1.3 is finally released the initial sync time will be greatly reduced.

As you have been syncing for 5 days I would just leave it a bit more of time to finish. There is an alternative solution, called "bootstapping": you download the blockchain file (consensus.db) from a reliable source so once you open again the client it just have to validate the chain, but not download it. It still will require several hours or even a full day, but it is less time than downloading the blockchain from the scratch. Follow these instructions: https://siawiki.tech/daemon/bootstrapping_the_blockchain