Everyone has been down this road, it's both fun and frustrating! Everything in your signal chain will have a color. If you're not getting what you like, replacing stuff can be a crapshoot unless you've figured out where your tone is falling down.
I'm not a chops monster. I'm not even all that stylistically flexible, really, since I've had the luxury of playing originals for 90% of my bass playing. But I do get fairly consistent compliments on my tone. And you know what? Everything I play sounds like me. Not the same, and not all at the same quality level, but almost never godawful and never "not me." So, I'd make sure of a few things before dropping money on stuff.
Do you sound good acoustically? On several basses? Do some basses sound good and some don't? Figure out why. Try and get your playing to the point where almost any decent bass has much of what you're looking for when you play unplugged.
THEN you're probably in a place to experience significant tone benefits from high dollar purchases. I don't want to think about how much money I spent back when I was just playing too damn hard to sound good no matter what I bought....
QUALITY is in your playing. Color, frequency balance, volume, and "spice" are in your gear. A+ playing is hard to mess up. C+ playing will never be more than a B- with stuff you buy.
