There are numerous homes available in Mesquite (87), and 75149 has a few dozen (46) homes listed for rent.
Of these there are currently are only 14 for under $900, and 12 of these have 3+ bedrooms.
You are going to have some push-back on the credit scores. Scores below 600 generally show an inability or else unwillingness to pay bills. The property manager or owner will examine the credit history carefully to see if any of the dings on your credit relate to paying for house-related charges, such as utility bills, rent or the like. If any evictions are recorded or judgments for back rent appear, it would be unlikely to be accepted into an owner's lease property. The risk would be high.
Good luck with finding what you're looking for.