Why can't I fall asleep even though I'm tired?

Something like this often happens because of some sort of stress in your life. If there is some sort of problem, talk to someone you trust, or try other methods of relaxing your mind before going to sleep

There´s a few tips and tricks for falling asleep more easily. First of all, you should not sit by a computer/tv/celphone before you are going to sleep, they keep your brain awake. Drinking hot milk works for some people and tea are supposed to be realaxing. Listening to music might be a suggestion aswell. If nothing works, you might wanna get it checked by a proffesional, that way you can get the help and medication you need.

Because that constant worry and anxiety keeps youse up and constantly eats away at youse resulting in youse not bein able to sleep at night

Usually it's because you have a lot in your mind, making your mind feel stimulated and keeping you awake despite feeling tired. Another possible cause is insomnia.