BlackWidow 2014 double-typing (and Synapse issues)

Hello, I bought a Razer BlackWidow sometime 4 years ago and until recently everything worked fine. However, a month ago my keyboard started double typing characters. First I thought it was the switches since it's rather old now, but I find it hard to believe that 90% of switches just decided to malfunction at the exact same time which led me to believe it's some kind of a driver issue. And that's when I found out that Razer Synapse doesn't even show any of my devices (I have a Razer Abyssus as well). I can confirm it has worked well in the past because I remember adjusting those pulsating lights through it. I however can't confirm it has been on Windows 10, maybe it was 7 or 8. I have tried all the solutions I could find - deleting Synapse entirely, uninstalling HID devices, deleting every registry entry connected to Razer, different USB ports, running the app as admin, changing language and keyboard options... nothing worked. Only thing I managed to achieve is to get my mouse driver showing correctly in the device manager, but my BlackWidow driver shows under Mice and pointing devices (although it is shown as a keyboard under Devices and printers) and therefore uses the Windows self-installed HID keyboard driver. So in the end, I still have a keyboard that doubletypes constantly - which made me spend more than 20mins writing this post - and my macro keys are useless since I can't map them through Synapse.