Maria, it is easy to take feedback comments personally, but you should not be stressing over your buyer.

When selling low value items you have to weigh up the risk of sending items with no tracking.

To send every item with tracking for PayPal protection would mean increasing your postage price or unit price, potentially losing sales.

vs

Sending items with no tracking and replacing or refunding any items that are lost in the mail.

Assuming you have to replace 5 items a year sold for $5 each it would cost you less than $25. If you want to cover this cost you would only need a small increase in your sell price. If you make 500 sales a year that would mean a 5c increase per item.

You need to work out at what value you send everything with tracking so if a buyer makes a multiple purchase you are covered.

Starting a business is all about taking a risk. Staying in business for the long term is all about managing those risks.