you paid a small amount of fee!
according to http://bitcoinfees.21.co/ you needed to pay 110 satoshi per byte and if you are saying the size correctly (20,000 bytes) it means you should have paid 0.022BTC fee for it which is ~$20
what you paid ($13) is ~0.014BTC

it will take a longer time to confirm mostly because there are 20K unconfrimed transactions right now (https://blockchain.info/unconfirmed-transactions)

you should wait but also try using this: https://www.viabtc.com/tools/txaccelerator/


here is an example for your curiosity 52135 (bytes)
https://blockchain.info/tx/ef492f5dd516f51061a77bc148b8925e74557b1f31a42ca51098f26b82c23fb0