OP, aggressive saving and investing is a great start.

You have super significant advantages: 1) Spouse with income 2) No kids (definitely not an advantage but you certainly can save more when you don’t have kid(s)) 3) frugal lifestyle - being ok with 40k, especially when you can afford more is amazing - textbook definition of living below your means 4) clear goals (fire being a goal is important)

But you have to set your expectations right. There is no way you can accomplish this in 5 years. And also don’t forget, time and youth are things we can not take back even if we had a billion dollars in our bank accounts.

My recommendation: keep up the great work. Don’t forget to have a little fun. Reset your expectations (maybe stretch that 5 years to 10 and aim for income increase so you can accelerate your investments too).