Seratonin overdose?

Patient: I just began taking a new supplement, 5-HTP 200mg time release. I have had severe anxiety and depression and do not want to see a doctor for prescribed medications so I have switched to this herbal supplement that converts into seratonin. I took 2 (double) tablets this morning to cope with extreme anxiety and am beginning to wonder if I am at risk of seratonin overdose? I am 135lbs