I can’t sleep more than 3 hours. There are ideas running in my mind everytime. I over think,?

Exam & Lifestyle. In order to rule out a possible medical condition, such as hyperthyroidism, associated with your sleep problem, I suggest an exam at a clinic. And you should make certain your diet is good with a lot of fruit, veggies, fish & chicken while avoiding too much sugar & caffeine. Avoid smoking & illicit drugs. Also try to get regular exercise. Meditation & counseling may also help. I wish you well!
Anxiety? I agree with earlier recommendation to have medical causes ruled out. Do you tend to be anxious or to obsess about things? Sometimes mental health services can help.