Needing a Change...

I need to vent. I need advice. I need support.
I have recently relocated across the country to a new job in a 40 bed cardiac ICU. I had 9 days of orientation to learn the ins and outs and was good to go after my first shift. After 5 years of ED/ICU experience, I was elated to start fresh, be challenged, and even bring something to the table.
Oops.
I find myself feeling very unhappy recently because I have yet to be challenged in the four months I have been working. I am really, really bored. I have repeatedly asked for a more challenging assignment, drips, a vent...something!! I had med/tele patients for 4 weeks straight.
Turns out, the LCNs thought I was a new grad.
Oops.
So now I am faced with a challenge. That of transferring to another unit in the same hospital to possibly have the chance to take care of an ICU patient.
Even so, the vent patients that I have taken care of still don't keep me busy. I turn every 30 mins, clean room, help others, audit charts, update care plans. I do it all and take pride in the quality of care I provide my patients and families, but I am bored stiff.
What, if anything, can I do? Should I go back to the ED? Try days for a while? I feel like without the constant running around almost losing my mind, I may be facing a career change.
I appreciate every response.
Yep, you might consider coming back to the ER. I've been where you are.