I accidentally sent my BCH from Breadwallet to a BTC address from my Trezor wallet. Is there any way to retrieve that back to my BCH wallet? The BTC wallet I sent the money to is mine, so I own the keys but the address starts with 3.
Following the steps from "How to claim your Bitcoin Cash (Bcash)" by Trezor Blog should do the trick.
1) Make sure Trezor uses latest firmware
2) Connect your Trezor
3) Go to Coin splitting tool
Since the Bitcoin address was already in the segwit format, you're in trouble. BCH does not support segwit, so it is difficult to build a BCH transaction to spend them and such a transaction would not be safe to broadcast to the BCH network— as on the BCH network it would be non-standard and could be doublespend with an "anyone can spend".
As far as I can tell, your only option would be to find a trustworthy miner whom you give the transaction directly that will include this non-standard anyone-can-spend transaction that sends the money to you, and doesn't just take the money for themselves. Also, you have to hope that no other miner replaces the block with another where they steal the money for themselves.
Since I'm not involved in the BCH community, I don't know whether there is any miner providing such a service at this time.