I joined near the start of this year and have loved every moment of it as well, except that I noticed a huge dropoff in posts starting in June. I was hoping it was just a fluke but now it seems that's been the normal amount of activity since then. I really hope things pick back up soon because while I still enjoy the game, it became slower-paced than I wanted really abruptly.

But the suggestions others made here are pretty good for finding people to tag, I think. I've had no problems making AC in any month. It helps to be proactive - make toplevels, make network posts, tag people's inboxes, and try to reach out and build lots of CR. I feel like it also helps to try and be social with other players on plurk or discord and I understand if that's not your thing, but staying in touch does help people stay interested in your character between threads.