This is just the start of a long emotional roller coaster.

Once you come on board full time you (and/or your wife) may find the uncertainty associated with income from a startup equally taxing. I do not say this to be discouraging but to get you to consider getting your financial affairs in order before coming on board full time (e.g. you may not be able to get any additional credit for several years once you are dependent on a new startup for income).

Anything you can do to lower your burn rate without compromising your obligations to your family is probably a good idea today. I think you would be much better served to continue part time and close enough business that you feel comfortable making the transition.