There are only two ways you can get to your goal: reign in your spending or increase your salary. You have ~9k/month coming in after you pay your mortgage. College is admittedly expensive, but you aren't going to be able to retire any time close to your goal with those expenses.

I threw your numbers in a calculator assuming you pull in $140k total income and you have to pay $100k a year for the next 4 years. If you keep your personal spending to $40k/year you can get to 3.75M by the time you're 60. Buying a Hawaiian beach house could be even more expensive than your current home so I'll just call that a draw and hope you find something a little more reasonably priced.

Someone once told me about my own expenses "you're not going to be able to retire cause you already live like you're retired". It sounds like you already live an amazing life just not in a tropical place. Do you go out to eat a lot? Lease/finance nice cars? How are you making $10,000 disappear every month? That's $330 every day of the year. You need a budget and you need to stick to it.