Check under 'Health and Safety' and 'If you have Problems' at https://www.oag.state.tx.us/consumer/tenants.shtml
In most states the LL is absolutely responsible to take action to exterminate bed bugs and to pay for it unless LL can show that a particular tenant introduced the BB to the property.
Additionally, you can take notify housing code enforcement--they can cite the LL for failing to take action.
Give a TX landlord tenant attorney a call--some offer free consultations--and discuss your situation and/or see if you qualify for free legal aid (Google 'Texas Legal Aid') call a couple organizations and discuss your scenario.
READ THIS BEFORE CALLING OR EMAILING ME: I am licensed in the Commonwealth of Virginia, addressing your issue does not create an attorney-client relationship and I AM NOT providing you legal advice. You should speak with an attorney to whom you have provided all the facts, before you take steps that may impact your legal rights. I am not obligated to answer subsequent emails or phone calls unless you have hired me. I wish you the best of luck with your situation.
The landlord is responsible. If you have sustained bed bug bites, you should retain a bed bugs lawyer by googling "bed bugs lawyer"....here, I did it for you... www.Bed-Bugs-Lawyer.com
John Lassen 1-877-252-4630