As you dive deeper down the worm hole that is photography, unless you have super human powers, you eventually suffer from gear acquisition syndrome. It's not always a bad thing though, when treated properly that is.
There you are, out creating photographs, all is well. You are having a great time perfectly content with the equipment. When you get home and look at your days work you are very happy with your results. You know that you have created something truly unique, it represents the world as you see it. You love your image so much that you want to share it with world You go to your social media of choice and off it goes. You are still happy with your image. Since you are online you decide to pa-ruse the inter-webs. It starts out innocent you are looking at others creations and taking bits and pieces of inspiration. Next thing you know you are on the dirty web sites, B&H Photos, Amazon, E-Bay, maybe even Craigslist. You don't know how you got there but you can't help yourself. You are reading reviews and stats for all of the latest cameras, lenses, lighting modifiers, and the list of photography gear that goes on and on. You have completely forgot about the images that you created just hours ago.
This is when the G.A.S. kicks in. Your photographs are somehow sub par as well as the equipment that you captured them with. You completely forget that it is you that created those images, it was your vision that sought out the greatest composition, you that waited for the lighting to be just right, and you that ultimately finalized your vision with editing. You did all of this work and all the camera did was record the image per your request, but remember you have forgotten this. You now need that next camera or lens or flash and until you do anything that you will create will be inferior. So you stop. You stop shooting, your creativity goes stale and you begin to doubt yourself as a photographer. Nothing has changed since earlier that day when you were happy with what you had and what you were creating, but now you have G.A.S.
How do you recover? How do you get past this feeling of inferiority? There is light at the end of the tunnel, there is hope. Look back at your images, in particular the ones you love. Realize that you make the biggest difference in your images, and also realize that if you stop you will only hinder your progress.
Now I do realize that there is a difference between your smartphones camera and a D4s or 1DX and there is a difference between a variable aperture kit lens and a 70-200 2.8 You can't deny that all of these examples of kit are useless without you, the photographer. You are the most important piece in your photographic puzzle.
As far as the good side of this "problem", well once you have reached the limitations of what your gear can do for you and you need to make that next step... this is a good place to be in. In this instance getting that next piece of gear will only further your photographic endeavors. Thankfully services such as BorrowLenses and LensRentals are there to help you decide if you really need that next piece of gear or not.
As stated before you are the most important piece of gear in your photographic kit, practice, visualize and above all Shoot What You Love, Love What You Shoot