Macbook Shutting Down Randomly

Hello,

Recently I've been having issues with my Macbook Air that are making it frustrating to use at all.

I'll be doing anything, whether it's browsing the internet, watching a movie, or even just listening to music and my Macbook will shut down without warning.

Actually, scratch that. *Sometimes* right before it shuts down, my Mac will make a loud buzzing/clicking noise, cutting out all sound/volume control. After that starts it usually only takes maybe 30 seconds to shut down, but sometimes I have to manually shut it down.

9 times out of 10 though, there is zero warning. It will shut down with no warning, and then when I boot it back up, it will have all my windows/tabs/etc. reopen as if nothing happened. It's gotten to the point where it's become a daily occurence, sometimes even happening several times in one day!

I'll be the first to admit I have been a bit hard on my Mac, and it has taken a couple of falls, but nothing seemed too messed up until this started happening about a month ago. I've reset my SMC, PRAM, updated the OS, etc. and nothing seems to really help. Is this a hardware issue from the falls it's taken or something else?

Thanks for any help!