What do I do if my sold item gets lost in transit?

So I sold something on ebay awhile ago, around May 31st, and they still haven't received it? They only live a few states away, so it should have arrived by now. Although, I don't have a printer, so I figured if I wrote the address on the envelope, it would work the same way, right? I knew that meant no tracking number, but it should be there by now. I don't know what to do. Am I just being impatient? Did I screw up by writing the address on the envelope instead of printing the label? I couldn't have printed it though...

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Idk. I'm just anxious because it was a $60 pokemon card and I don't want it to be lost. Is it possible they just didn't accept the package as received so they don't pay? They already paid though, so that can't be right. Idk, my anxiety is all over the place