I had an interesting conversation with someone not too long ago about how they want to collect on a larger scale, but just get overwhelmed with the task and had given up multiple times. I had two pieces of advice to offer. The first, and probably the most important, is to take a good look at your goal and make sure it's something that you actually want to invest the time and resources into. Collecting something like a full library can take years and thousands of dollars. If you're not committed and have stalled or even gone backwards in that goal, is it really something that is important to you or simply something that used to seem enjoyable, but maybe isn't quite what you though it was? Even on a smaller scale, such as collecting all the games from your favorite series, can be a huge task. There are dozens of games across multiple platforms in series like Mario, Mega Man, Final Fantasy, Zelda, Pac-Man, Harvest Moon, Pokemon, etc. Beyond the time and money, you had better enjoy research and have the space available in your home to display or store them like you want to.
If all that checks out though, then my next suggestion is to enter the delightful world of Sub-Sets!