Everyone has a different physiological make up, doesn't mean that one person is better than another, we're just all different, I say that because what I'm about to say I don't want you think I'm better than you. I've always had this weird way of not being bothered by unfortunate events, even before I went into the military I was like that, during the military I did certain things that was required of me to do that I don't discuss but you I'll let your imagination run wild on that one and I can tell you, you're imagination will not be able to run wild enough! Later got into (non professional) racing cars and a solo horrific accident, then encountered other stuff in my career that would have probably drove some people insane.
So how did I deal with this stuff you scream? I have no idea if this had anything to do with why I can do what I did, it could be just innate in me, but when I was kid of about 7 or 8 (I'm now 65 so that film is now old), I saw a movie about the war in Korea, one of the guys in the film gets shot up bad, and he's shaking and can't move because of fear mostly, his squad leader comes up to him starts trying to talk to the guy but can't get him to responds, screams at the soldier to "square up Marine" which mean't to prepare yourself to fight to the death, they needed him to fire his weapon till he was dead and no longer able to, and the Marine did just that killing a few N Koreans before he got shot some more and died. That scene, which is about all that I remember of the film, stuck with me for all these years, that no matter what happens you have to face the problem head again and again if need be. It's like this, when you're a baby and you take your first attempts at walking you fall down and get hurt well you don't just lie there after falling down and never get up again due to anxiety! no, you got up as a baby and faced your fear and walked again only to fall down again and again and again and getting hurt over and over and over. Same thing happened when you got older and started to ride a bike, you didn't quite riding a bike just because you fell down once. There is something about a child that they can face fear and not let it scare them, as we get older we begin to over rationalize these things that hurt us and develop fears.
So when something like that happens what happened to you I highly recommend that as soon as you are physically able is to ride your bike in that exact same location at the exact same time if possible, at the same speed as well. When I had my horrific car crash I got into a friends car and drove it at high speed at that same track that same day (I got real blessed by not getting killed or hurt in the accident that should have killed me, but I've always been blessed in life and death situations, sometimes I got hurt but never killed obviously! LOL!!)
I'm not a head shrink, I don't know anything about how the human mind works, I've see first hand how the human mind fails under certain circumstances due to fear, but I can't tell you why one person's mind won't fail and another does, but again it doesn't mean that the one person is better than the other, they're just different. When I saw guys uncontrollably freaking out I didn't look down on them during or after the situation, I can't say other guys didn't look down on them, but I didn't, because I knew everyone is different and some people simply shouldn't be in certain situations and they don't find out till they're in it. But those are extreme situations, your situation is no where near that extreme, so the only advice I know to give you is to face your fear and re ride that same route alone, I don't buy into doing it in a group, you were alone the first time you need to be alone the second time. I know that may sound like weird advice but I'm also pretty sure it will work, I can't guarantee it of course, but everyone that I've ever known who faced their fear were less fearful in the future, those that didn't never learned from that fear and were fearful in future events or simply gave up doing whatever they did that caused the fear, and that's not a good way to lead a life.
I'm sorry if I sounded harsh or hard or whatever, I just want you to find a way of becoming a better stronger person because of the experience you had and not a worse weaker person because of it. If you can face it, you will become a better stronger person in ALL that you do in your life going forward.