There's a dent (like there should be) on one side of my nose and not the other? (photos)

If you're open to considering surgery, this can be helped by performing a rhinoplasty operation.  Be sure to discuss your goals and concerns with your board certified plastic surgeon and consider the pros and the cons.

Your nose can be made more symmetrical with open rhinoplasty. For whatever reason, you nose developed asymmetrically. It appears as though your lower lateral cartilage on the left is weaker than the right. From the pictures it looks like what I would do is reduce the right side a bit. This will make a normal-appearing concavity  to the right side and then strengthen the left side with a cartilage graft from your septum. Because your overlying skin has some memory to it, it will want to go back, so I'd say you'll get about 90-95% correction of this, but it won't be perfect. It will look perfect for several months, but then it will want to go back. But if the STRUCTURE is fixed underneath, it will only go back a small degree and you should have a dramatic improvement in your nose symmetry.