Unfortunately, I'm not going to be able to tell you what you want to hear.
Texas will restore partial gun rights 5 years after the completion of your sentence. But all that means is that you can keep a gun in the house in Texas. You may not take it anywhere outside of the home.
Also, the Federal government does not recognize a partial restoration of gun rights. That means you would not be able to pass a NICs check. You would have to obtain a gun through a private sale. And even though you have a rights to have a gun inside your home in Texas, you could still be guilty of a Federal offense if for any reason the Federal government had reason to find it there.
The Federal government will restore your gun rights after an expungement, set aside or pardon. But in Texas, you would have to be pardoned first to get your conviction expunged.
So to get your full state and federal gun rights back, you'd need to get a pardon from the governor of Texas. Any former Texas offender can apply for one without the need of a lawyer. You can read more about this here.
Pardons are hard to get, but once you have one, the Federal government will lift their bar against your gun rights and your state and Federal rights will be restored in full.