Hi sir, recovery from a typhoid fever is always a painful and slow process. Body pain, stomach upsets, nausea are very common upto 2 weeks post treatment. Mouth ulcers can be due to deficiency in micronutrients due to 1.less absorption of micro nutrients by intestines during the fever period, also 2.due to bland food during the fever.(which lacks nutrients)
I hope doctor has given a multivitamin tablet to continue now, if not please buy one, eg: tab. Zincovit or tab. Atoz others also available in pharmacy. Do not worry, ul soon be fine, its very common with typhoid or lepto fevers, so do not worry.