HELP! MacBook Air doesn't work properly

My macbook air always shuts down right after I close the lid for like over an hour, then I cannot turn on the laptop. I tried the reset SMC and PRAM and it works. However, it then just hapens again and again the same thing. It seems like I can't leave my macbook sleep for several hours (during the time when I don't use like sleeping), because it will shut down.

It's been like this for a few days now and I'm so tired that I have to do the resets again and again. For the record, sometimes the resets dont work though. I have to wait for several hours, then come back to reset and power on, then the screen will show up and work properly.

It's so depressing because I don't know when the time it's gonna turn on and I can't work with it. If anyone have a great solution, please, let me know.

Thank you in advance!