Legal Question in Criminal Law in Texas

Not anymore. Even if you had appealed at the time, your plea bargain would have left very little for you to argue about.

You can still try to petition for a writ of habeas corpus. Here again, though, the plea bargain will be a serious obstacle. There are very few types of arguments that are even theoretically available after a guilty plea, and I have no idea whether the facts of your case would allow you to make any of those arguments.