I have so much yet feel so empty. Why can't I keep away from ideas of easy escape?

19 [f] I don't know what's wrong with me. I have so much. I have a decent family, nice friends who are always there, etc. I have a good life recently and people always tell me that but nothing seems good enough. I didn't have the best childhood, I was bullied by boys, my dad had drugs issues that destroyed my parent's marriage. It was rough. I try and put on a smile everyday and keep going but if I see some sort of way to end my life, I think about putting it into action. For example, if I am walking on the sidewalk, I always imaging walking into oncoming traffic, or when I am standing at the top of high building withs balconies I think about jumping, or how easy it would be to just hang myself in my closest. Theses thoughts scare me so much and yet the more days go by, I can only tell myself that if things ever do get THAT bad I can just end it. I have that power. I don't know how to stop this. I have seen a therapist but stopped. I have never taken medication either.