I had negative on the Abbott IGG antibody test too. My GP is unsurprised and thinks that very few under 40s are getting the antibodies. Not sure what that means in practice.
I am still ill unfortunately. But slowly getting better. Back living with my parents, which is much better than being alone like I was for 3 months... although challenging in a different way. Things do feel like they are starting to move but I have a lot of fatigue, tinnitus, sore throat, weak voice, on off crazy head and face pressures and as of 3 weeks ago - body twitches and movements. Been trying to listen to music and do light dancing, some gentle regular movements, humming singing and making sounds etc... had a good cranial osteopathy session yesterday too. But Im not well enough to work or do my masters. Or even go for a proper walk. It really sucks.