Below, I linked a video which shows you how to recover your Steam Account if it got hacked, stolen what have you. I posted this video 2 years ago in Activity but, with time, it’ll get lost. Either way, it’s an older video and I’m sure there’s newer methods if this method fails. If you've found a new method of as to how to recover your steam account, leave the info. below. 
https://youtu.be/tJx94iuy_eg

*You can also find this topic in the Information Technology Community Group