I'm 22 and about 3 months ago I started lactating. I'm not pregnant and my prolactin level was as high as 185. What could be the causr?

Probly pituitary. A high prolactin can be caused by certain meds (esp. Psych meds), marijuana, renal failure, pregnancy, nipple stimulation, chest trauma and others, but generally a prolactin of that level (185) is due to a benign pituitary tumor. Speak to the doctor that ordered the test. An MRI may reveal a tumor. It can usually be treated with medication.
It depends. The most important thing to check for is a pituatary tumor. It also could be caused by medication, particularly antidepressants. See your primary care doctor and he or she can directly to the next course of action needed. And sometimes this just happens, but it does warrant further investigation.