I have just realized that a sync is not a backup. I synced my phone days ago, but backed it up months ago.
Is there anyway to get my synced text message history back?
There was some really important info on there.
If you didn't backup your text messages on iPhone previously, then it might be tough to recover.
I would give the free trial of Tenorshare iPhone Data Recovery a shot to see if you can recover the lost messages.
I know you said you didn't backup your iPhone, however maybe try running the free version of the software on your computer just in case it might recognize any old backups that possibly exist. Hope this helps!