It's not either/or. We can exercise choices within the limitations of the system, but we don't have omnipotence or we would basically be gods. Think of it like playing a video game. There's a lot you can do in the game but your choices are limited to the interface. You're not totally trapped but you also aren't totally fluid either. I find that "spiritual" people tend to spiritually bypass the limitations and act like everything is free, and then they deny their human level experience; and I find that hard determinists get so rational and controlled in their expounding of the issues that it's too entrapping. I tend to take the middle road.
For this reason, it's neither free will vs. deterministic. It's co-creative. You get to decide what you want to do with the hand you are dealt.
Fundamentally, there is no point to anything. None whatsoever. You could take that to a nihilistic place and live there if you wanted, and a lot of people do. Since everything is pointless then living is just a chore, and that leads to cynicism. Or you could take it to a stoic place -- it's all meaningless but you have to be brave in the face of that meaningless, while swallowing your pride.
My solution to existentialism is realizing your creative potential, within defined limitations, and exploring where the boundaries of those limitations are. Life is full of expansion and contraction at various stages, all signifying nothing. Sometimes we cause our own suffering by believing a limitation exists where there is none, and sometimes we jump almost fatally into life with the assumption we are a free and then get struck down by a boundary. The only way to know is to live.
Meaning is something that you get to apply to your circumstances, and you have virtually limitless capacity to apply meaning. It is your one truly free virtue, and its own limit is your own creativity. According to logotherapy (founded by Victor Frankl, who I highly recommend reading into if you want to get some good insight), the only way in which humans are truly free is in our freedom to apply meaning. Two people being tortured may not see it the same way. Two people living a luxurious, pleasurable lifestyle may not see it the same way. Either way, it all turns to dust in the end... but while you're here you get to decide what it all means to you.
The struggle to find meaning is what defines human existence, and not anything objective. So I would further your statement to say... yes, humans are scared of having choice, but I would say the fear runs much deeper than that. Humans are terrified of the fact that nothing they hold dear really means anything. Most refuse to look into that void because it means a real ego death... it's the death of career, family, friends, relationships, "purpose", self-identity, all of it. It is the death of concepts, if taken to its ultimate conclusion. If you can really face that void and come out the other end, then you will realize this:
The bad news is that nothing means anything. The good news is that nothing means anything.
Most people only want to grasp at the good things in life because it reassures them away from this void. Existentialists are a step further along in that they see the pointlessness, but most of them are afraid of taking it to its ultimate conclusion because they don't want to experience the apocalypse it can produce. A minority actually go through the death (usually not by choice, i.e. they have a life threatening illness, get tortured, or put into prison for a long time), and when they come out the other side they have learned how to abide in the emptiness in equanimity. These people are usually very content.
Good luck... you are asking difficult questions, but at least you have the courage to ask them. According to what is meaningful to me, you are doing good work.
