A: Your mental and physical health are, in my opinion, the most precious gift you can give yourself, your children, and your husband. What does he want you to do, stay in a situation you hate just so you can continue to make more money? There is nothing—I repeat, nothing—irresponsible about how you're preparing to achieve this goal. You've given yourself a three-year buffer to clean up your balance sheet and enact your plan. I'm so impressed at the care you're taking in anticipation of this life-altering move. So many women who hate their jobs come to me ready to quit tomorrow without a penny saved. You're a great example of how to move toward change in a sensible way.
Your husband is the one being irresponsible. He should value your dreams over your paycheck. Besides, even though you were earning a lot, you still had credit card debt and no emergency savings. Unhappy people often spend, spend, spend; people who are satisfied with their lives don't need money to create a false sense of well-being. If you follow your passion for interior design, you'll be more content in your professional and personal life. That's good for your health, good for your head, and ultimately great for your family. Will you have less money? Only time will tell. But even if your income decreases, I bet you'll find you can make more out of less.
By the way, don't be angry with your husband. My sense is that he's just fearful of change and worried about making sure the family will be okay. Over the next three years, you'll have plenty of time to talk about how to make this leap.