Have you been to a doctor to make sure your problems are not physiological? I say this because the first thing that popped into my mind when reading your symptoms was “depression”. Especially the “fallen out of love with the world” and “lost my zest for life”, as well as your sudden and inexplicable anti-socialness. Please go to a doctor and be evaluated to ensure you are not suffering from depression, as it is very hard (not impossible, but not easy) to pull yourself out of depression without some type of help, whether it’s drugs or therapy or meditation etc.