I feel your pain, although to some extent this is a common problem - one person (the DM) more invested than the rest (players). Occasionally you'll luck upon a group of all DMs/diehards, although that can have its own problems!
When I was younger, I loved being the primary DM. In a later long-term campaign during 4E, in my 30s, I did it because A) Like you, I was the most invested in the game, and B) When others tried their hand at DMing it wasn't as successful. And certainly, there was a certain gratification to being the guy that everyone wanted to DM in the group, but it also became irritating handing out even just two-page campaign guides and quickly realizing that no one (or only one or two) actually read them.
But I think your thread title is key, and I will expand upon that. For me, my favorite elements of playing D&D are actually the world-building, and very quickly--back in the late 80s/early 90s I realized that this energy was better directed into writing and world-building for my own pleasure. So my interest in D&D diverged: On one hand, there was the game itself, whatever campaign I was in, whether as a (mostly) DM or (occasionally) player; this would vary, with many hiatuses of a year or three over the next three decades. On the other, the creative practice of imagining fantasy worlds and stories, which became my own personal project of world-building and writing that is completely separate from D&D.
The former became more of a hobby - a fun past-time, and one that I tried to temper my expectations and investments to no more than moderate. The latter became my passion.
Maybe you don't have the same interest or inclination to channel some of those energies elsewhere, but it is worth considering. I love playing D&D, but I don't have to play - I can enjoy it on occasion, or even just playing attention to its development and buy the occasional book. But
need to be creative, and to create worlds and stories in those worlds, and I can do that regardless of whether I'm actively playing or not.
EDIT: It isn't unlike dating. Problems usually (and often) arise when two people have different degrees of investment. But I think it is important to get a sense of this early on. If your group is into something more casual, and you can adjust yourself accordingly, then there's nothing wrong with a bit of "casual fun" (ahem). But if you want a long-term, invested commitment, don't waste your time and energy if you're not getting reciprocation. There are other fish in the sea, after all!