As a CNC Machinist/operator, I can tell you that running production work sucks, regardless of the industry.
From 2004-2010 I worked at a gun shop, same handful of parts day in and day out. Mandatory 60 hour weeks for 8 months straight. Made over 130,000 Bushmaster/YHM AR-15 upper receivers my first year on one particular machine. Never got credit for anything, no attaboys, no thank yous. Started at $7.50/hr., left at $17.50/hr. for something better.
2010-2013 I worked at an aerospace shop, started on regular production but quickly got moved to more of a R&D prototyping position. Lots of job perks but the owner was a p***k. Better pay and unlimited overtime. Taught myself to program, taught myself Mastercam. Every job was different and it was always challenging and interesting, kept it fun and new. Clashed with my boss one too many times and it cost me the job.
2014-present and I'm at another production shop that works mainly for the oil industry. Work is plentiful, but the monotony is back and it's not challenging. Took a $20,000/year pay cut for this job but it's the only place that wanted to hire me. I'm running lathes now, before this job I really only ever ran mills. It's cool that I'm learning lathes now, but that's the only thing that makes it interesting. Once I know lathes as well as I know mills, it's going to be tough to do this day in and day out. I'm only 29 and I'd like to think I can stay in this industry until I retire from it, but I also know that I get bored easily. The fact that I've done this since I was 18 is a feat in itself. The only other jobs I've had were 5 years of farming during the summer while I was in school, and a couple months working under the table for a small mom-and-pop automotive repair shop in 2013/2014 after I lost my job at the aerospace shop. That work was fun, but it was more hell on my body than anything. Not that being a machinist is much better, but I digress...
This type of work is almost nothing but monotonous, it's the same task all the time. What I've learned so far is that prototype work is the only real way to have variety in this industry. If the shop that I worked prototyping for had it's s*** together I'm petty sure I'd still be there and I'd still be happy with my career. But, it's all I know, I didn't go to college for anything and formal education isn't my thing anyway.
I don't mean to sound like such a Debby Downer here, but production work is exactly what it sounds like. You show up to make things and count the hours until you can go home. There isn't much fun to be had. I can say that a job like this can be very comfortable, you get very good at the tasks you're assigned to and it becomes second-nature. If the feeling of comfort stays stronger than the monotony, then embrace the comfort and don't look back.
I do hope you find something that works for you, I know what it's like to be in that rut, but I'm also too lazy and stubborn to work to get out of it.