I always struggled to understand the fear of success until I read into it. It's an interesting phenomena, though it sounds more so that you are describing fear of failure when you state something like:
this mostly happens to an average traders or business owners which they likely say, "what if one red trade takes it all alway" they suddenly become more anxious having that fear that they might start all over again.
Though both can be remedied by mental health. I've had quite a rollercoaster in life and I can tell you that I have performed best when my mental health has been best (surprise, surprise). Eating a clean diet, getting a satisfactory amount of exercise, taking time to touch grass and even to meditate, spending time with family or friends, or making new friends and socializing, might all seem like consuming time that could go toward success, though ultimately the mental clarity that they can provide can help you to be more efficient.
If you have any unhealthy habits like alcohol, substances, gambling, or anything that is difficult to quit, these will be your biggest hurdles toward doing all of what I've described. They might seem necessary to cope or to be able to work harder than someone who does not do these things, or that they provide some sort of edge, however in the long run they don't. They cost time, they cost money and they cost health. All of which you can do without.
If one is truly thinking that the next red might mean the end of it all, that sounds like a problem with risk management. Small wins and losses from smaller risks are easier to manage and deal with mentally in comparison to putting a large chunk or all of it all on the wire. It takes both discipline and skill to be able to manage small wins and losses, to win more than lose, and to stick to that in comparison to risking it for the big win.
It is all advice that has been said time and time again, though personally, I can attest to all of the above beating fear of failure - and I'm sure it applies to fear of success as well. Mental sharpness is key to attaining success, no exceptions in my opinion.