What wallet are you using?
If you are using electrum, use a resend by Fee, or CPFP,
Increase the transaction fee. This is only possible for ‘replaceable’ transactions. To create this type of transaction, you must have enabled ‘Replace by Fee’ in your preferences, before sending the transaction.
Create a ‘Child Pays For Parent’ transaction. A CPFP is a new transaction, that pays a high fee in order to compensate for the small fee of its parent transaction. It can be done by the recipient of the funds, or by the sender, if the transaction has a change output.
Go to your tools, preferences, There's a place called fees, click that, enable RBF.
Right click the tx and you should be able to increase the fee and rebroadcast.
If that doesn't work, try to use CPFP
~/~
If you are currently using blockchain.info, export & import your private keys into electrum, & do the above.