How can I unstuck a transaction sent from Mycelium?
First, find the transaction on a blockchain explorer like blockchair.com or blockchain.info and make sure it appears as valid. If it isn't found, it wasn't broadcast at all by your wallet, and you can find many free broadcast services here.

Assuming it is valid, has been broadcast, then find a free transaction accelerator (don't bother paying the ones that ask for a fee) and enter the transaction ID and usually you'll see it get confirmed. I recommend the ViaBTC Accelerator*  or creating an account at AntPool (free) and using the AntPool accelerator.

Be patient. It can still take a few hours or so.



* You'll have to time it right. They only allow a handful per hour.