So this happened to me 2 days ago, i haven't done anything that could change my headset microphone. I tried to play a game with my friend and when we got into a game he said he can hear himself and that he could hear my in-game sounds but he couldn't hear me. I've tried a lot of things but none of them helped so if you guys have any idea what's going on with my headset please respond.
Try another headset on your computer. Test the microphone.
Try your headset on another computer. Test the microphone.
Determine if the microphone problem follows the headset or stays with the computer.
What OS are you using? Windowsw 10? Use the built in troubleshooters. The troubleshooters may find and fix something.
Right click the small speaker icon usually shown in the lower right screen corner. Many options: windows, tabs, drop downs, properties. Explore first and keep notes. Then change only one configuration setting at a time if some setting is not as it should or you otherwise expect it to be.
Failing that, reinstall and reconfigure the audio drivers.