Welcome Sylvara.
It does sound like your HDD is failing.
First thing I would do is order Recovery Media.
When you receive the Recovery Media install the new HDD and install the New OS.
After you build the new OS use one of these SATA to USB connectors to transfer any pics, music, documents etc.
Connect your old HDD to the cable then just plug it into your laptops USB and copy from the old HDD and paste it to the new HDD.
REO