I’m not sure whether you can file suit online in Texas, but even if you can I’d recommend contacting an attorney first. I’m an Illinois attorney, but I know attorneys near you if you’d like a referral. You should be able to get a free consultation.
As I am licensed in Florida and Vermont, I cannot offer you specific advice as to Texas state law. I would respectfully recommended that you immediately contact a medical malpractice attorney in your area and pose this question to him or her.