Symptoms- Lots of tiny little mouth ulcers, fatigue, hair loss, headaches. What could be causing this?

For the last 6 weeks or more ive been getting lots of tiny little mouth ulcers all through my mouth. Some start to heal but then new ones form. Ive also been losing a bit of hair for the last few months. Aswell as feeling fatigued %26amp; getting headaches. What could be causing these?Symptoms- Lots of tiny little mouth ulcers, fatigue, hair loss, headaches. What could be causing this?
id say u best get to a dr!!!