Extreme Fatigue and Joint Pains. Advise!

Hi my father is 66 yrs old. He is suffering from extreme fatigue & body (joints pain) from past more than one week now. We visited General physician & blood tests were carried out. CBC is normal, LFT,KFT & Thyroid is normal, His Hba1c was 6.4 and all values of Cholestrol was high and Iron level was 45 (Only 3 values were Abnormal). Later he had lost his appetite and was having pain below right chest so we consulted Gastroenterologist who did USG scan abdomen & pelvis which was normal except for slight increase of liver size. Later he carried out endoscopy in which he found one small gastric ulcer. He has been taking multiple medicines like dolo, hifenac p, gastric tablet, Cholestrol tablet, BP Tablet, Metaformin for sugar, gastric tablet and syrup for ulcer etc. But still his extreme fatigue and joint pains continue. Not knowing wat to do. Pls advise