I am 34, my salary is 79 k and my job satisfaction is 0. How can I make a career change quickly?

I am 34 yo software engineer. I have 4 kids. I work in a company that’s doing great, they pay well, the people are great, the company is growing fast. However I woke up this morning and I realised that I didn’t have fun doing my job since years. It was not the case at all when I joined. I used to have fun but today I just feel like I’m doing the same routine over and over and I have zero fun. So I probably need to switch to something else. This is a big problem. Because I feel like I’m 34 now and I have to get a lot of things done before I am old. So I am afraid that I’ll waste a lot of time and I’ll be always in the same position. So how can I quickly get excited about my career ? What are the best career ever for software engineer in terms of happiness ?