One of the distractions of the hobbyist photographer is the Gear Acquistion Syndrome (GAS): instead of making photographs, you spend all your time obsessing over new gear. Your current gear seems inadequate when there are so much better options available.
This is not exclusive to photographers: I’ve seen at least guitarists and cyclists do this, too. Basically there are two distinct versions of these hobbies: the main hobby and the gear hobby. There’s nothing wrong with this. When it comes to your free time, you do you.
Why does Gear Acquisition Syndrome cause distress, then? It’s because your priorities and actions are in conflict: you’re focusing on the gear hobby when you feel you should be focusing the main hobby.
I’ve had my bouts of photography GAS, but I nowadays get easily over it. Let me share some of the thoughts that helped me.
First, clarify your priorities. Instead of thinking of what you should do, think about what you want to do. Should is sneaky, beware should! Myself, I care about making greats photographs much more than I care about having a great camera. Some people may find that they in fact prefer cameras to photographs. This is fine, too.
Once you understand your priorities, think about what’s the bottleneck in your process. Have you reached the limits of your gear? For example, I could buy a new digital camera with a bigger sensor. The sensor size is clearly something that people care about, as evidenced by how enthusiastic people are about the new era of medium format digital cameras. Despite this, I’m unable to argue how this would make my photos better. The sensor size is not my bottleneck – the time spent on photography is.
Finally, it’s helpful to study the old masters. It’s easy to forget how amazingly good and easy to use everything on the market right now is. Compared to the modern equipment, the photographers of the early and even the late 20th century used convoluded crap. Nevertheless they managed to make pictures that speak to me decades later. Your current gear likely is good enough for pretty great photography.
Of course, it’s easy for me to say this. My photography is decidedly non-technical. So maybe you do need that new lens after all…