Classic Upgraditis denial
All kidding aside, I wouldn't say that you need 2 years or 3000 miles to know if there is a problem. But I think your problem has more to do with
how you use your gears rather than gears themselves.
Here's your gearing (or a reasonable approximation) again. Click on the tab that says "Teeth" and you'll get a drop down menu. Pick "gear inches" so that we are on the same page and I can walk you through it.
First let me say that your gearing isn't optimal. Yes there are gaps. More gears fill in some of those gaps but the equipment, as we've said above, costs more. Going to a 50/34 doesn't close the gaps, it just makes them wider.
Let's say your are in the 6th cog (21 teeth) and middle ring...gear inches (GI) 49". If you move to the large ring, the GI is now 62" which is a big step. If you were to upshift in the middle ring to the 18 tooth cog or 16 tooth cog, the transition to the outer ring is the same but it
feels smaller. It's hard to explain why but it just does.
On the other hand, if you want a fairly cheap upgrade, you can change the chainrings. If you change the middle chainring to a 42, you end up with
this gear pattern. (Again, click on the "gear inch" tab). With this pattern, a click in any direction will result in the same change in GI. Shifting from the 42/16 (chainwheel/cog) to the 48/16 is the same gear as shifting from the 42/16 to the 42/18. It feels incredibly natural. The only downside is that you have a higher middle range.
On the other hand,
if you change out the outer ring to a 44, you get the same effect with a lower high gear. But a 119" high gear is really, really tall and probably unnecessary.
I would suggest playing around with either gear pattern before you go and swap out all the equipment. Chainrings are fairly cheap.