It sounds to me like you have everything going for you. The only thing I can think is that you may have a fear of rejection or failure? I`m not trying to be an amateur psychologist here, but that seems to be a problem for many people in getting started.
I started my business (solo practitioner) 11 years ago. At the time I didn`t really think about it. An opportunity came up so I just took it. I have had ups and downs over the years, but I cannot imagine no longer being in charge of my own destiny. I trust my livelihood to myself (with all my shortcomings) rather than a nameless bureacrat in an ivory tower in some corporate HQ.
Rejection is not failure. It is just being in the wrong place at the wrong time, but every rejection is a potential future opportunity, if handled well. And I like this quote from Albert Grey: "Successful people make a habit of doing what failures refuse to do".
If the business is perfect for you, you have your business plan, and you have the environment for it, I personally cannot see how you can fail. You will be having too much fun to fail.
Does this help?