Do as hang says and contact your carrier. They keep copies of every text sent and received for legal reasons. Ie, the police suspect the phone has been used to traffick drugs. They would get a warrant and the carrier would supply them all the messages.
They can resend them to you if you request it, so long as you can prove your identity and ownership of the phone.
Do not call a third party company, they more than likely can't help, and quite possibly steal your identity. I repeat, do not trust third parties.
Closing this thread now.