First of all, don't put things around, try to store them in the real estate bought in the eight main cities. For example, I am used to storing things in the storeroom of Guanhu or Hulachen Manor. There are many boxes in the storage room. I can sort them and look for them when I find them.

Secondly, if what you lost is related to the progress of the task, you can consider entering the console to enter coc qasmoke to find a copy in the House of Everything, and then entering coc riverwood from the console to return to Ximu Town (if you remember the English name of the town to hand in the task, you can also go directly to coc). Generally speaking, a replica of the House of Everything should help you complete the task. If not, you can only read the file.