USB - C will not function to charge or connect external devices

Hi All,

I am no longer able to use my USB C port other than to connect my charger directly to my 13" Macbook (early 2015).

I had had a "Service battery" notification for a few months, but the battery would still charge and the USB C port still worked in terms of allowing external devices to connect via a USB C adapter with charger and USB input ports.

Then, about a week ago, I noticed my computer started to turn itself off every so often. While browsing for possible culprits, I came across someone who recommended turning FileVault off and then back on. I did so, but somehow in the process, something was affected resulting in my battery not charging ("Battery Is Not Charging" appears in the dropdown menu), and, moreover, I cannot use my adapter to connect anything external. This is very problematic for me, as I have most of my storage on an external HD.

I have tried resetting NVRAM and SMC multiple times, both through key combos and via Terminal. No dice. When I do so with the adapter connected, nothing happens. When I do so with the charger hooked up directly, either nothing happens, or the battery icon appears on screen as 100% charged, only to revert to the same situation described above one the machine boots up. The machine is also fidgety as far as booting up. Sometimes it will not respond to the power button at all, and multiple attempts are required to boot it, including disconnecting and reconnecting the charger cable.

Would reinstalling Mac OS possibly revert me back to a usable machine? Or does anyone have any other advice?

I am leery of purchasing a battery replacement kit since the problem may be greater than just switching out the battery. Additionally, my Macbook just went out of Apple Care coverage (of course), and I am currently in Mexico, where the local Mac Store charges $450 to replace the battery for me. Yes, you read that correctly. In Mexico, tomatoes are cheap, but Apples are very, very expensive.

Thanks to anyone who can chime in on this. Any help at all is welcome.

David