What is success for you? Why does it matter so much? Why are the stakes so high? American society idolizes extremely wealthy, very social, extroverted, entrepreneurial married people. But that's not necessarily right for you
What I sense from this is you're looking to be validated and accepted as a human being for your future successes. Because at present you're not very accepting of yourself. Maybe? I may be way off?
I've been there a lot. I even achieved absurd work/social/sexual success for my age. However it always felt so empty. So desolate. I thought the solution was more "success", but I kept feeling even worse.
The solution is trusting yourself, trusting your body, trusting your intuition - rather than looking at who you think you should be. When you need to please other people, it's very very exhausting and draining of your energy.
Personally, I'm a sensitive soul. I'm very introverted most of the time. I probably won't be a super-successful billionaire tech genius. But I've found some meaning in life through writing (about the human condition) and settling into a comfortable rural Spanish town. I've found a lot of contentment here creating art, writing, playing and having lots of time.
I don't think you have a fear of success. I suspect you don't really want success in the way you imagine/describe it I sense you've had to become a person who you're not, to survive. Pleasing parents/teachers from an early age. You weren't allowed to develop into an independent individual who trusts himself. You weren't allowed to argue and fight for what mattered to you. You couldn't win against the adult oppression.
So to survive you took on society's definition of a successful life. Except it has required all kinds of strains and stresses. Subconsciously you know success in this way (driven by external validation) is empty. But you keep striving towards it because it keeps you busy, and distracts you from the potentially devastating hurt that you haven't been allowed (by your caregivers) to exist for who you are. Instead you've had to wear a heavy, ill-fitting persona. Your whole body, being, energy and organism has been under intense strain to fit into this mould.
The solution is to get it out. Write privately. Cry. See a psychotherapist . And trust yourself. Trust your body and it's cells. You're not alone and none of the above is your fault. It's just you doing your best to survive in what was a hostile atmosphere.
A period of great transformation may follow where you may have to be frugal and make changes. You may feel terrible for some time. But eventually things will get better and you'll redevelop your internal strength and energy. Then this will lead to the success you really want.
Sorry. I don't know how much of this post will resonate with you. I may just be projecting my own thoughts/experiences onto you. Anyway, take what resonates with you from it.
This is a video you should watch