I leveled ACN to 30 about a week before 3.1, but by that time I had around 40 leves. I had been playing other games in the interim to build them up. I got WHM to 50 in about two very casual weeks of play, but I had the MSQ for that, which you've already done.

Are you also doing all of your guildhests and hunting logs? Guildhests give you bonus experience the first time you run them as a class.

Check around and see if you have any quests here or there to do. I deliberately leveled CNJ in Gridania, THM in Thanalan, and ACN in Limsa areas deliberately to cover each one.

Maybe you can do DoL gathering while you wait for queues, or get into crafting. Or both! Make a little money and maybe stave off some of the boredom.

Balmung may also be a problem for you as well, it's a Legacy server, so it probably started with a lot of people at 50 on multiple jobs when ARR released. You also don't have much circulation in players, with it being nearly 100% closed to new players and transfers. Do you have any attachment to Balmung? If not, maybe consider a server transfer.