It's hard to fall asleep because i keep thinking about different things. what should i do?

See your doctor.: You sound like you have a lot of stress or anxiety that may cause sleeping disturbance. It may be an issue of depression. Need to see if you need medicine or counseling. If this has been short lived you might wait. . If is going in to longer such as > 2 weeks see your doctor.

Insomnia: Try some physical activity prior to bed so when you relax to go to sleep you will be able to before thoughts flood your brain