believe me, you're not alone. Many times I have had the same problems. However, for me, it is an easy fix:
When I log on, I see first what I need to do, then what I want to do. If the needs are not desireable at the time, I move on to my wants. At my level, my current wants are farming, getting my AF, skill-ups, Promyvion, Genkai 3. As such, I generally hang out in Jeuno for a while, waiting for possible shouts from people wanting the same things.
If no such thing happens, then I start my own shouts.
If still nothing, then I move on to something else that can be soloed.
If all else fails, then it's time for some random Notorious Monster Hunting and/or exploring; just for the heck of it. :)
This game offers many avenues to get your thrills from. Usually, there is something for everyone to enjoy at any given time; you just need to find it first.
If all else fails... Then don't stress. Simply take a break from the game for as long as needed until you get your groove back. I'm rooting for you! ^^