I will advise you to import the private keys using the electrum wallet,
verify the wallet before using and make use of the manual fees option.
Instead of just importing the wallet into electrum, it would be better to create a new wallet on electrum and send all the fund to that.
Also note that trustwallet allow you to adjust the fee rate manually too.
If you want to make a transaction on trust wallet, after you have pasted the address and input the amount of coins that you want to send, click on 'continue' at the right upper connect that will take you to the next page to finalize the transaction. Click on the setting account on the right upper corner to customize the fee.
Trustwallet is not an open source wallet, you do not know how the wallet developers come about seed phrase generation, maybe there is a backdoor for the developers to know the keys that Trustwallet users are generating while using Trustwallet. That is one of the reasons it is advisable to send the coin to an open source wallet before believing your coin safety.