Talk to General Physician on Fatigue And General Tiredness

Hello doctor! I am 18 years old and I feel very tired all the time, especially in morning when all people feel fresh after waking up but i do not. I feel that my joints are extremely hardened after waking up but this becomes normal after an hour or two and hair loss is also increasing day by day and sleep cycle is disturbed. On google i saw that these symptoms may be of low testosterone level and i thought my testosterone level is low. So i got myself tested but my testosterone level was normal i.e 5.44 ng/ml. Now the cause of tiredness is unknown to me. So please guide me about what my problem actually is and how can i cure it. Note: Recently i started taking multivitamin Berocca.