My daughter is on 5htp (50mgs at night with food) she is 5ft tall & weighs about 83lbs(we're in metric so I have to try & convert from 38kgs) so you may need to adjust your dosage if you're alot bigger?? It also comes in 100mgs. I don't know the details re this.
Her dr also (he's apsychiatrist but tries natural therapies first whenever possible) has her take a gentle 30 to 60 minute walk at sunrise - at this time there's something in the suns rays (even if it's overcast) that works on the brains chemicals to reduce stress.
He also recommends yoga & or pilates or similar for stress reduction & to help you learn to control stressful situations on the spot.
Lastly omega 3 oils, viatmin b6 & you might also want to look into the supplement dhea which he also recommends (it just isn't appropraite for my daughter due to her being very underweight due to stress).
Good luck.