If you've backed up to a cloud account etc then they should hopefully be there.
If you haven't then they are probably lost as your network won't retain text message content.
There is paid for software out there pertaining to claim it can recover lost data but as one not used them I can't recommend any I'm afraid.
Current Phone ~ Samsung Note 9 Model: SM-N960 Duos 512Gb
Samsung Gear s3 Frontier Watch