At best SH is a temporary coping strategy. It can provide a feeling of control to push back at anxieties. There are other strategies that can also be temporary. However, at some point the anxieties may have to be addressed. Anxieties can be carried from childhood such as from an abusive home life. They can be situational. Anxieties can also be intrinsic such as with an overly sensitive neurology. Sometimes anxieties can be learned such as with a college philosophy student who considers he can't prove he exists.
Some people try to tackle uncertainty head on. Others try to nibble at the fringe. You might find trying to exercise more direct control over some aspect of uncertainty or apprehension and see what successes you can muster. Even small successes at driving back the gloom can be self-reinforcing.
Some people use religion to give themselves certainty. Some use activities or athletics. Some immerse themselves in their work or studies. Others find having a large family demands so much attention that uncertainty is driven out. Younger people who have not started their own families yet can find that time hangs heavy on their hands. In these cases things like volunteer work can be a useful way to both fill time as well as gain a sense of control from helping others.