Thanks for the detailed response. What does rebroadcasting the signed transaction mean?
Here's the raw transaction in hex format:
010000000001018fe98535907adfa51d1aed325e35b10d95c763b47c1afe24db75897b21531de201000000171600147a2e7c4dc861b09a433427fb89448fc8e0dc8625ffffffff02a1fae3010000000017a914940861d25bbcf28d376f29b1931318790e1aa63f87893c32f20100000017a91476e8b55e723f764a18f60844fe8bbffee03c164d8702483045022100ca918af5b29338d26db56aaec81a8564b5334e0bcf55b91bec3a34f77caab911022012fae0271b380d4c3e6b15576b8f5985f7f624af8f622961db7ef0e3f0dd24190121036c492ad7e625a58c5ea6b28319e4af12d9111d32d13fdb186ccba3f50cbb050200000000
Use google, or Vod's thread to search for free services that allow you to rebroadcast a bitcoin transaction (there are dozens of these services), copy the transaction above and rebroadcast it

The theory behind this action: if you create a transaction, it is broadcasted to the nodes in the network. Some of these nodes are owned by mining pool operators. The mining pool operator picks the highest fee transactions (in sat/byte) from the mempool of his node to fill the block he's trying to solve.
The default setting of a node is to remove unconfirmed transaction from it's mempool after x hours (my node is set to 10 days). So after these x hours, most mining nodes won't have your unconfirmed transaction in their mempool anymore... Unless you re-broadcast it to the network

This theory also shows there is no need to rebroadcast to often... Once every 2-3 days should be sufficient