You can't win if you don't play.
Unless you consider sitting around with an unproduced script 'winning'. And some folks do.
Who are you going to send it to... directly... for a guaranteed read, that is going to offer you a six figure deal right out of the box? "Uncle Bob's Garage Studios"? I don't think so.
It will cost you forty five days of 'waiting'. Frankly, the first two weeks, I doubt they'll download it. They seem to be running about two weeks behind in reading.
Worst case scenario - nothing happens. But, that's what you've got right now... nothing happening.
Next case scenario. They like it, option it, you get 10 grand, and the right to brag "My script was optioned by Amazon..." - That's worth something. It's a brick of credibility in your career. While Amazon sits on it for eighteen months, you're out there shopping your next great script as an 'optioned' screenwriter. Plus you've got ten grand to show for it. THEN - Nothing happens. The option expires... you still have the ten grand, the script is back in your hands, and the right to say you HAVE optioned a script. You're an 'optioned writer'. Yay.
(Speaking as an optioned writer - yeah, it makes a difference in opening doors.)
Next case scenario. They extend the option -you get more money - then nothing. Yay, same as above, but with more cash.
Next case scenario. They option it - hire out the re-write. Someone else comes on board, makes some money - gets attached. You share credit. That's how it's done in the business... especially for first time writers. Then.... nothing happens. The option expires, and that version of the script is dead to you. You get back your original version - and all the benefits of having been 'optioned'. Yay.
Next case scenario. It's optioned. YOU do all the rewrites for sole credit. It gets made. You make a bunch of money. YAY. It groses over 60 mill BIG YAY... more money. Lots of bragging. Academy Awards dress decisions haunt your dreams.
Next case scenario. It's optioned. Others come on board for rewrite. You share credit. It gets made. You make the SAME money... but share credit. Pretty typical in the business. Now your Academy Award speech has to be shorter. YAY.
'Worst' case scenario - they make some version of your script - that is wildly successful... but you are somehow 'pushed' down to 'story by' or 'no' credit. You make a ton of money. You can tell everyone it's based on your story. And you have proof. Still get bragging rights as optioned writer. Still get ton of money. Believe me that will open doors.
(All of this is assuming you're submitting 'privately' - and not going the public route. I believe that's what you have expressed.)
Tell me again what you're 'afraid' of?
Success? Or the disappointment of not being noticed?
You can't win, if you don't play.