To avoid paying it? Die penniless. And you will need to do that pretty quickly as well.
Sales taxes are trust fund monies; it was NEVER your money in the first place. You were no more than a temporary custodian for the State for those funds. As such, it cannot be discharged in bankruptcy either now or 20 years from now. Old income tax debts can be discharged in bankruptcy, but NEVER trust fund tax debts.
You need to get on a payment plan with the State and clear it as quickly as possible. If you don't, the State can and will start going after your wages, bank accounts, and even your home. Under TX law, few things can attach to your homestead but taxes are one of those few things that can.
The bottom line is that you
can't afford NOT to work out a payment plan with the State and clear it as quickly as possible.
An LLC, or any other business entity, does NOT shield you from taxes. The business' principals (you and any partners or company officers in a corporation) are ALWAYS personally liable for all tax debts of the business.
Trust fund penalties are steep -- upwards of 100% or more -- so you have little grounds to argue the point with the State. If there are any missing Sales Tax returns, get them filed ASAP to establish the base liability or the State will estimate the tax and proceed against you from there. They may entertain abatement of some of the penalties for economic hardship but you have to work with them. The worst that you can do is ignore their demands for payment.