You are not alone in your difficulty in delegating responsibilities - at least you have this self-awareness and the luck of a trusting team who tells you what they need. "The best executive is the one who has sense enough to pick good men to do what he wants done, and enough self-restraint  to keep from meddling with them while they do it" Theodore Roosevelt.
 
When people walk into my clinic with delegation problems, we look at what delegation means to them, what tasks can be delegated easily, the potential advantages of delegation , the roadblocks that are holding them back and the techniques of how to delegate. Delegation is when a manager or leader transfers authority or shares authority and the responsibility that goes with it to an employee or subordinate. Delegation is not just telling people what to do. With new responsibilities, there must be the authority to carry the tasks out but all must retain accountability for the outcome.

Like any supervisory skill, there are many background facts we need to learn.  There are definite advantages to being a stellar delegator but one needs to know what to delegate and how.