What you are going through sounds eerily similar to what I went through, but I was in the retail food/drug industry. You get to a point where you start thinking just a little longer and I can nest it away and start looking, or go back to school, or it will get better. If you don't love it now (yes, not like, love) it won't get better. I'm not saying leave but you need to know what your tolerance level is.
Willing to relocate? Family issues to consider? Can you afford or are you willing to take a pay cut to start something else? Keep your resume updated and send it to anything that even remotely looks interesting, or will give you experience to re-invent yourself.
All totaled up I did 20yrs in retail. 10, 9, 1. The last was a different form of retail but I quickly learned retail is retail. Sure it paid good and there were lots of good times but I always wondered if there was anything more available. Left it all, started back to online courses and a job hunt. Landed a job that was a HUGE pay cut but offered experience in installation/tech work. Just landed a new job that pays comparable to what I used to make, day 1 benefits, opportunity for growth, overtime that pays instead of salary, and I don't have the headaches of management. Don't get me wrong, it's been a long process to get to where I am now but I am now doing something I enjoy daily.
As for leaving, don't give indications and go out on top of your game. Once you make your decision to stay or go it will be easier to focus on what you want to do. And try not to burn bridges if you can, a lot of jobs are researching previous employment history further and further.
Good luck in your search.