Being an INTJ, and a personal assistant, these are my recommendations:

1) Take the excellent advice that Alky has provided and keep the two tasks separate. The possibility of blurring the lines becomes less risky if you ensure that your health and your business interests are compartmentalised.

2) Write down exactly what you want your assistant to do. We are 'J's', lists come easy to us... Do you want your assistant to have access to your email and calendar? Are you looking for someone to format and edit your reports / correspondence? Do you need them to be able to network? Research assistance? Event planning? Provide structure and establish processes to ensure your business lives on after you? Nothing is too great or small.

3) Once you have your list decide if you need a physical or a virtual assistant. A lot of those tasks noted above can be done from an assistant online with the right access, but not all. If a virtual assistant is probably all you need then start looking in India, or the Philippines, and start talking to providers. The benefit of a virtual assistant is that your interaction with them is largely by text and video calls when necessary and you don't need to have another person in your space. Well, that and the US dollar has a decent amount of weight again.

4) Probationary Period aka "try before you buy". Establish the understanding that it is for both of your benefits to put in place a time for you both to get used to each other and the job. If it doesn't work then you're not contractually obligated to keep them. The value in a good assistant is rapport... if you like each other and there is a good working relationship then the chances are higher that you'll get a good result.

I'll stop there. Approach the problem with some rationality and you'll be fine. x