There are hundreds, if not thousands, of aspirants out there. It's a tough business to get into. However, since you claim to not want fame, it's a lot easier to get into being an extra or the kind of actor who is called on for little scenes, for crowds and the like. I went to High School with a gal who does that. She's the masseuse in a quick spa commercial, or wears a nice dress in a party scene, or she's another mom at a playground or whatever. She very rarely has lines. She has an Actors' Equity card, probably from some commercial she did at one time. She, of course, has a day job. The kind of work that she does is not enough for anyone to make a living at.
If that is not what you want, then seek out acting classes - more of them. You took one in college. That's nice. Now take another five or more. Work on getting into productions, either at school or in the area. There are usually community productions of some sort. You need to get into these and really see what kind of work is involved. A few middle school productions are not enough, and they don't give you a true picture of what's truly involved.
It really, really helps if you can sing, as a lot of local productions are less picky about bringing more people into a chorus if you can prove that you can sing. Not just - you think you can sing. You have to be able to sing, so I would suggest taking voice lessons, too, and make the most of what you've got. I would also suggest taking dance. Even if you never, ever want to do a musical, even fight scenes require some form of choreography. Plus it will help you to move better.
I do hope you're taking care of your body physically. As in, working out, eating right, getting enough sleep, lifting weights, and not smoking. Yes, there are overweight people who act, but there are a lot fewer of them than there are fit people. So if you're not fit now, you need to get that way. It's easier when you're younger (trust me on this one), so get into good habits now.
This is effort. It is work. It's not something you can just slide into without further ado. Even my pal who acts in the occasional commercial still watches her weight and takes classes when she can - and she's in her 50s.
Best of luck to you.