On the surface it was selfish but it did give you a new lease of life - both the action and the car - and that was valuable to your relationship with yourself, your husband, and your children. You say money doesn't buy you happiness. I agree that it doesn't as a rule but it can buy you ways to lift your spirits.
It sounds like it was a great move and you and your husband presumably came out the other side of this difficult time in one piece eventually?