From OP's older, deleted post
I can receive calls and all texts. Sending MMS works, sending SMS fails.
@"Lbeaster11"#p214858
It'd be better to add a comment to the older post rather than create a new one. Commenting: "bump" (the name of this action) or "anyone have an idea?" Suffices. It'll place your post at the very top for people to see.
First try mobile settings reset:
Settings > system > reset mobile network settings
Then reboot
Reinstall your texting app if you can. Also logs helps with pinpointing the issue. Your text history is in an android database--not the app's--so you won't lose any messages.
Going to your carrier can help in this situation. They can help you navigate the various possible causes.
Or try stock OS. Back up anything important which would be deleted.
Or telecoms in China don't provide updated connectivity info to AOSP. If that applies to you.