Do you plan on being the tow truck driver or do you plan on hiring someone?
How much research have you done?
What does a tow truck driver get paid?
How much can you reasonably expect to make per quarter?
How long can you afford to take losses until your business starts to pay?
How long do you have to store a car in your state before you can file a lien on it and take possession and auction it off?
There are many more questions to be considered.
If someone was to ask me, I would say plan on keeping your job and hiring a part time driver to get started. With the education that you say you have, your time is worth more then a tow-truck drivers time, you should not be in the truck (I really need to take my own advice sometimes