but again - have you ever gone to a dietitian or a nutritionist or anything like that?
you may feel 'pointless' cause your body is suffering from malnutrition. - suppose you're missing vitamin K (or whatever - B12, C - whatever) - and that affects mood.
your life feels pointless cause maybe your nutrition is so poor your brain can't think straight and now is like in 'zombie' mode.
i'm not saying that if you start eating cheerios your outlook on life will be brighter - but until you verify your body is metabolizing correctly and what you're eating is supplying your brain w/ all the nutrition it needs to feel comfortable, you don't know.
(its just a suggestion and i'm not a nutritionist or anything like that)