To be scared of changing job after 8 years?

[Aabbaas]

I have been with my current company for 8 years. Had the best time for the first 6.5 years or so and never once thought about leaving (regular promotions and a supportive manager).
Then, my manager left, team was restructured and I was overlooked for a promotion and everything went downhill (well, in my mind it did). I lost motivation. I still love the company and its culture but don’t feel like fighting for a promotion anymore. I am still doing a good job but mainly coasting (get away with it as I know my job and company well). I can see new team members coming from competitors being more valued. I think I just became part of the furniture really.
So I have recently started applying for jobs and to my surprise, I have been immediately invited to 4 interviews with different firms. 3 of them went very well and have progressed me, with one of them now being at final round.
Now that things are looking more real, I feel a bit scared about leaving. 8 years is a long time and this is the main place that shaped who I am professionally but I also made some great friends. I have worked in some horrible organizations before and never want to relive that again.
I also have a 4 year old DD and current job offers me plenty of flexibility. I am conscious that being the new person in an organisation takes a toll on you in terms of workload and mental capacity and also as much as I can ask the question, not sure how flexible these companies will actually be.

Is it normal to get cold feet?

Think about whether you will regret not taking a new job (if offered) in a few months time. Change can be scary, but you aren’t happy or fulfilled where you are, from what you say.

I feel institutionalised really. Not unhappy but not excited anymore, lack drive, work on autopilot, no longer care. Agree not a great place to be despite liking the people and the culture

You know the answer op, you're still young, take the plunge using the info you have , do they offer some flexi, wfh, online reviews, find out about their culture as much as you can.

Ok its a risk and you might find the new place awful (worst case scenario) but you will still gain new skills and learn so much more about work dynamics etc. Stay for a year then move on if you hate it. Your CV can take it by the sounds of things. You've got this.

I absolutely hate change but a couple of years ago I left a job I’d been in for 23 years. I was absolutely terrified, convinced I wouldn’t be good enough etc. You know what? I absolutely love my new job. By day 2 I’d settled in and realised id found my tribe.
You can do it.