Laptop sleep mode and ethernet problems (can't find solution on internet)?

Hello, I have a Toshiba Satellite P-750-BTG422 (1.5 years old now) and all at around the same time, I noticed several irritating issues which may or may not be related. Several days ago, my laptop's ethernet capabilities stopped working (recognizes the cable most of the time, but no network identification; ethernet to USB adapter functions fine), my laptop started getting unusually warm only in the bottom left corner where my ethernet cable is (regardless of whether it's plugged in or not), and now, even when I put the laptop into sleep mode (slowly blinking LED, no fan activity, black screen and all), that area remains warm (too warm), my battery life is drained far too quickly for sleep mode, and when I put my ear up against my laptop at the one spot, I hear this odd and faint whirring/whining noise.

My guess is the issues are connected and their is something faulty with my wireless/LAN adapter. I've tried restoring my system back to the earliest profile I have available, updating windows and my network-hardware drivers, tried automatic troubleshooting, tried messing around with my power mode settings, tried cleaning my fan, tried changing my network address in the adapter's properties menu, and I've tried resetting my TCP/IP. None of these nor any amount of reboots have done anything and I have no idea what could be the problem short of hardware failure (and I am past warranty). Any ideas? Thank you.