Background:
I work as the only bookkeeper/office manager in a local small business. As such, most of my work is self-managed with little to no direct supervision, and I am considered the "right-hand lady" (a term he has used) to the owner, my boss. So long as I can produce certain reports when my boss requests them, and so long as the power is still running (meaning the bills are paid), most of my work goes unnoticed (but not unappreciated). I also have some flexibility in my shifts so long as I accurately track my hours, as my boss spends most of his days out of the office.
Over the course of the month of October, I have been struggling with work due to my father being in and out of the hospital after a serious heart attack. My boss is aware of the situation and I took off a day or two, or left early a day or two, with his knowledge in order to handle these issues. Even when I am at work I find myself on the phone to coordinate health care, or to communicate to people that need information. (Note: I'm located in the U.S. and am therefore also dealing with the financial repercussions of my father's illness, as well as essentially being his caretaker while he recovers, since he can't afford an in-home caretaker.)
I have begun to realize that due to these personal problems (that I have unwillingly been bringing with me to the office everyday), the quality of my work has suffered over the course of the past month. I am very behind in terms of projects that need to be completed, and a couple of items will likely not be finished by their deadlines.
The Question:
I want to "come clean" with my boss, I guess you could say, and tell him honestly that I have not been meeting expectations of my job over the course of the last few weeks, but that I intend to make it right. In the course of this "confession" I would also like to ask for some leeway at work, to get caught up on projects and to express that I cannot take on any extra projects until I am more stable.
My question might end up being too opinion-based, but I would really love some feedback from previous or current managers. I looked over a few questions, namely this one, this one, and this one. I feel that none of them had the answers I'm looking for, and most of them were closed for being opinion-based. I'm hoping that my question doesn't fall quite under this scope. I really just want the best and most professional method to deal with the issue, as this has never happened before in our working relationship. If the question does end up closed, I can definitely accept that.
How do I make my boss aware of a personal situation without having him lose trust in me as his employee?
In addition, I thought it would be easiest to write everything out in an email, and let him read it at his leisure, and then speak to him. Would this be considered unprofessional as opposed to approaching him face-to-face to speak to him? What method is best (especially in a boss that is hard to pin down for one-on-one meetings) to speak about something very personal and very likely negative?