Hi, I've been away from the board for awhile, but thought I'd reply. Your scan sounds exactly like mine was 18 months ago.
No uptake on one side of your thyroid means that side is just slacking. Your Hot Nodule is working overtime. Your TSH tells your thyroid to get busy. The lower your TSH, the more your normal thyroid slows down. But that hot nodule will not follow the rules of the TSH. It just keeps going.
After you get that hot nodule taken care of, with surgery or radioactive iodine treatment, the other side of your thyroid can wake up and start working again. Mine did. I just take 50mcg levo to give it a little help.
Hang in there. This is a rather long process to get back to normal.
Often that is the case when the nodule is on one side only. It is like the two lobes are acting independently of each other. I had about 10 nodules on one side and Hurthle Cell adenoma in one of those, but the other side had nodules which had no Hurthle Cells.
Your side with the nodule is more than likely trying to cope with the nodule in it and probably producing excess hormone, whilst the other side is more than likely just plodding along normally.