I just made an offer on a house but now my landlord is refusing to let me out of my lease (in Texas). We only have one month left. What are my legal rights? I've been told that if you buy a house you can legally cancel your lease agreement. I haven't been able to find anything about this on findlaw. And if I move out, can she make me pay rent and take my deposit for leaving early? Or can I just leave the deposit to pay for the final month of rent?

As far as I know there is no law in any state that allows a tenant to terminate a lease because they are buying a house. That is an urban myth that we see here constantly.

If your lease ends in one month then give the landlord notice that you will not be renewing. You will only be responsible for that month of rent and any damage to the premises beyond ordinary wear and tear.

If you have just made the offer on the house then it is unlikely you will close on the purchase in less than one month anyway.