Hello, Joint pain along with stiffness and fatigue has different causes like infection, autoimmune disease related. I would suggest you visit a rheumatologist for these symptoms as there is a need for physical examination and detailed medical history as well as some blood tests to check for rheumatoid factor and other autoimmune disease markers. Along with that x-ray of the involved joints is advisable. Weight loss might be associated with the cause of these symptoms. The physical symptoms you experience might be the reason behind you getting irritable and depressed. So for this, once you see the rheumatologist, after getting diagnosed and with appropriate management the symptoms will resolve slowly. You can also visit a psychiatrist for a couple of counselling sessions which might help to cope with the depression. Along with that, I would suggest you involve in physical activities like yoga, jogging, walking which help in relieving the stiffness as well as regularly meditating helps to elevate the mood. Also, when things bother and drag you towards depression, talking to your friends and family members is always the best thing to do. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Manisha Auradkar, General & Family Physician