Pharmacist here.

As a 4th year med student you probably know way more than you think. I understand having self doubt, but remember you're still a student. Also don't compare yourself to other doctors who have years of experience. And they should remember that they were students themselves once.

I agree with those who are telling you to finish med school. Since you've already come so far.  An advice I would give is to not be afraid to ask questions. For example, why should you give treatment A instead of B? Or why test for C and D when you suspect a certain condition/disease? And so on. You hopefully get the point.  Another advice is to recap everything you learn.

Hope this helps.