It hurt to read that, because I am experiencing that too. The curiosity is long gone and with it the fun and the motivation too. A lot of things feel samey, overall I feel jaded, tired and most of all nostalgic about the past, where it wasn't like that. Desperately I cling to the stuff that brought me all the positive feelings and experiences, but most of the time it doesn't work, I just do it out of habit. I honestly don't know what to do, I have no motivation, no creativity, no interests, I simply browse multiple imageboards, sleep, work out, play vidya, watch anime, read, cook and work, day in day out.
Several times I have read that there is new input necessary, a new hobby, to meet new people, best case even both. Not only do I have no idea how this should be possible, it is also quite difficult when more than a decade of Internet fucked you up to the point that all the things going on in real life don't bother you at all anymore.