Hello I understand your concern. Burning sensation in feet with aching in legs can be due to Vitamin or mineral deficiency/diabetes mellitus/peripheral artery disease. As you say you are malnourished,cause may be vitamin b12 or B6 deficiency.It needs to be diagnosed through blood test and then it can be managed by theurapeutic doses of vitaminB12 tablets or injectiions. I would like to know if you have history of alcohol/tobacco addiction or if you are on any medications?As these may be cause of your symptoms. Get certain investigation done like blood haemogram,fasting blood glucose,blood lipids,serum vitamin B 12 levels. If the pain or burning sensation in legs come on walking and lessens on rest,it can be due to peripheral artery disease.In that case,you may also need to Doppler scan of blood flow of legs. Further management depends upon the cause diagnosed through above investigations. Take healthy diet with vitamin supplementation ,with adequate hydration for general wellbeing. Hope this information helps. Any more query is welcome.