I was born into near poverty, grew up that way. We always had food and clothes, just not the newest or the best or tons of anything. Bikes were second hand that my parents fixed up for us, dolls were hand downs that my mom sewed new dresses for and fixed up the hair somehow, stuff like that.
Then when I started out for myself, I found I didn't need all the stuff I thought I did. I was content to be what most people would call poor, but I still had plenty of food, clothes, and things I truly needed. The rest was just degrees of 'wanting'. Yeah, I 'wanted' a new pickup, but the older one that was paid for was plenty good. I 'wanted' a new lawn mower, but the older one that ran fine and cost nothing was plenty good.
I also learned how to make something comparable to things I wanted but could not budget for or afford. I remember when wooden shelves with the decorative brackets came out, usually painted crackle finish or antiqued. Couldn't budget for them but I could scrounge up wood and using a borrowed router and some sand paper and paint, I learned to make excellent copies for just a few bucks. That is just one example, but learning to make things that I wanted but couldn't afford taught me some skills along the way, too.
Now as to knick knacks and doodads. I am guilty of finding cute things every now and then, but I don't pay a lot for them. I don't think it hurts to buy something like that every now and then.
Donno if I answered your question or not. I'd just suggest trying to wean yourself away from the 'wants'. That's a hard thing to do. Maybe you could learn to make copies of things you want, maybe try some woodworking, quilting or sewing, things like that. Right now, I've gone nuts over antique game boards. I can't afford to buy them already done, so I get pine 1x12 wood and use a ruler and some stencils I cut out of a coffee can lid and make my own. Stencil some of the designs and freehand paint the rest. It's a lot of fun.
Something else I thought of is maybe if you really want something, to try going to all the thrift shops around you, maybe you can find what you want there for a lot less than you'd spend buying it new. Thank goodness for used bookstores, or I would really be in a bind.