Write it down, make a plan.
The unfortunate reality is that people hold these beliefs not because they are true, but because they desperately want them to be true.
Self-destruction is perhaps the most common behavior there is. We would all like to believe nothing is our fault and the world just sucks, and such a belief is very comfortable. But we form that belief because it is easy, because it requires no thought, and because it ultimately hurts us.
Being a failure is easy, being a failure that's not your fault is even easier. Trying, winning, is hard. Lots of people would rather just not play at all. They think doing so will help them, because winning is hard. But it doesn't, it's just self-destructive.
It's like not showing up to an interview because you're worried it'll go bad. Yeah, it might. But you can't get a job you didn't even interview for.
It’s the definition of having to “get back on the horse” after falling.
I agree but the fear is based on something, not only on rejection. There are quite a few issues happening at once I think:
1) Relentless economic/status competition. The more unequal the society the more this is pronounced, this can cause a huge burden on a relationship where one side is more successful than the other side. This can cause you to feel Schandefreud when your friend is not doing well which is the opposite of what you're supposed to feel; most people don't want to feel these twisted feelings and might prefer to withdraw from the friendship. Others will "endure" their friends' success and a small minority will be 100% happy for them without any feelings of inadequacy.
2) Our culture of instant gratification - friendships and all relationships are hard work, we don't seem to like doing that anymore.
3) Friendship instability - people move cities, countries or simply change and will look for other people to be friends with. That causes an emotional rollercoster and could cause people to ask whether it's worth it . Many friendships don't survive 10 years.
4) I guess a summation of all previous points is relentless individualism in the West and the death of community, religion and even somewhat family. If some of us can't be botehred to visit our parents more than once or twice a year it's not a shocker we can't be bothered to do the hard work required to maintain personal friendships.
There could be more things going on but I think it's much more complex than simply fear of rejection.