To file a successful claim, most policies require you to inform the insurance company soon after an accident. Be careful when you contact them, though. You don’t want to say anything that can be used to justify the reduction or rejection of your claim. Stick to the objective facts - time, place, date, etc.
Do not provide details about how the crash happened or the extent of your injuries. Answer questions, but do not offer additional details. If pressed about your injuries, saying “I am being medically treated” is more than enough information.
Remember: You do not have to communicate with the other driver’s insurance company - so don’t do it. Texas is a “fault” state, which, in general, means the at-fault driver’s insurance company is liable for paying damages. When they contact you, they are looking for reasons to blame you for the crash and reduce your payout.