No doctors on this website, but you've already seen one and assured you're fine. I'd be more worried about your thinking processes and possible anxiety problems. Everyone has had erection problems at some point here and there and they don't rush right out and buy something they know nothing about. They don't pop more than the directions call for. They don't buy a supplement they know nothing about. And they don't obsess over a problem after being told it isn't a problem. It sounds to me like you're possibly having an anxiety problem that predated this experience. If so, that's the problem that needs your attention. I'm also unclear that you had an erection that lasted that long. You say you sent to sleep. Now, I'm an old man now, but I've never been able to sleep with an erection. So either you were drunk out of your gourd or is it possible the erection went away, but you woke up with one, which is really common as testosterone in men is highest in the morning? Just asking.
Yes, I would absolutely believe a doctor who examined me and saw nothing wrong than a generic list of possible side effects of things that may possibly happen.
Those things CAN happen - they aren't absolutes. They didn't happen to you. Don't push your luck and take the pills again. Be grateful they didn't happen and trust your doctor who actually examined you and saw nothing wrong.
Like Pax, I'm concerned about your thought process and you saying you feel like ending your life. That's a strong reaction to this. I hope you consider getting some counseling.