Sometimes the job environment is what makes a job so precious. You could be in a job where everyone is competing for favor to the higher ups and lying and cheating and being mean.
Perhaps taking on a second part time job could help you have a bit more spending money.
Selling things on ebay isn't very productive because the hours it takes to manage the sales pages then the fees and stuff....well, a person is lucky to make $100 extra a week. My friend does this and she spends up to 18 hours per day on her sales items. It's not one of the good things to make extra money. BUT if you sew or do crafts on order then perhaps someplace like Etsy could be great for you.
Throwing a daily newspaper only takes a little while each day and it gives a steady extra income. Renting a booth in a local craft shop is not a bad idea. Going by once per month or so to dust/update the look of the booth is often all the maintenance it would need.
Editing papers for students, typing up papers for professionals, and other things you can do in the evening while relaxing after work.
I think if you have any happiness at all with this job that you need to consider what another job environment might be like. Again, sometimes the job isn't all that bad once you see what you might have instead.
If you truly want out and can't stand it anymore then get your resume out there and start going on interviews. Let your boss know before you send them out though. Here's how I'd handle it.
"Hi boss, can I talk to you a moment? I like working here and I like my job but I'm unable to make it on this income. I want to save money for retirement and build savings. I hate to leave but I want to let you know I'm updating my resume and am going to be sending it out. Just so you know what's going on if you get some inquiries as to my job history."