how to let go?

I am a control freak, perhaps more than that. I like things done my way and I am always happier to do them myself to ensure standards are met. When I love a project, I have a hard time delegating to others. I don't always doubt their capabilities to do the project, but they lack the passion I have for my work. My current job is one I somewhat created for myself, therefore it suits me 100%. I have tailored it over the past 6-9 months to be exactly what I want to be doing at this time in my life. I have worked very hard to ensure it still exists in its same capacity through 3 managers and a new director. It has been a constant up hill battle but I am finally making amazing successes with long term goals within my company. Preparing for maternity leave scares the hell out of me. My job is not text book, so someone could really F it up. My vision is delicate and needs to be nurtured constantly and the up hill battle is only getting steeper with the infiltration tactics I have planned for this position. I fear this new person will lack passion for my job, will lack the same vision and goals and will leave my job without the successes I have planned for it. I also fear that I am not prepared to train them to take over as I have been so busy with work, that I haven't had a moment to realize what it is I do. I managed to secure a 1 month transition for this job, which is huge at my company. There are often, too often, gaps in hiring of a month or more in length. I started the process of my replacement last year to ensure I would have coverage. So I have one month with someone new to make them my minion and to ensure their success, which in turn ensures my own success. I know they need to be up and running and working on a few of their own projects before I leave....and it will be hard to release the power.

I always thought it would be cool to have an assistant, I am not sure I could handle the sharing of tasks.