Hi, do you remember what you were doing last before the messages got deleted? Unfortunately there may be no way to retrieve these old deleted messages anymore. With phones like the LG GH-255G, messages are usually stored only on the phone memory with no backup copies, so once deleted they are lost forever.

And as for sending pictures via MMS, you are likely getting that error because the picture you are trying to send is too large. You can try either resizing this picture or sending a different picture entirely (one that is smaller) to avoid getting the error.