Hire & Fire

Lately I'm not happy at work. It's not the work itself, it's everything surrounding it.
Our departement manager sucks, he annoys everyone with his ignorance and stupidity, and he has hired a girl for my team leader who's not qualified for the job. She's not a team player herself, so she knows nothing about how to lead a team and is doing an awful job at it.
Our company has problems and fired some people, among them some in our departement and in my team. And now another team mate has quit (not surprisingly, she didn't get along with our team leader either). Which leaves our team down from 5 to 2 - my team leader and me.
I work in a mail order company and for some reason there's a rather hostile attitude towards eCommerce (where I work). It results in bad cooperation and last week comparatively many people from our departement were fired, which makes no sense considering the development away from the catalogue towards the internet. It doesn't give one the feeling that this company fit for the future, and the mail order business in Germany is in a tough spot anyway, with two big players already down.

My mum keeps telling me that I should look for another job. But I wasn't sure. I like the work I'm doing and there's some benefits to working in this company, like a 37,5 hrs working week.
But if it's annoying me too much and making me unhappy, should I not leave?
I don't know where to go though. I'd be fine with getting out of eCommerce, I never wanted to work in this area anyway, it just kind of happened. But I like the flat I'm living in, I like the city, it's close to my hometown; I really don't want to move again. And since there are hardly any jobs for me in this city, the alternative would be commuting.
I guess I should start updating my LinkedIn profile...

And another thing I'm worrying about: what if the next place isn't any better? I thought this place was better than the last, and though I like the tasks better, the working environment got worse and worse. How can I know it's not the same at the next job?

I wonder whether I'll find a job that I'll like, even after years, a place where I can stay. Or will I have to change jobs every 2 or 3 years? I don't think I'd like to live that way.