Why won't my car move in drive but will in reverse and gears 1,2 and3?

What is your question?

I have an 07 buick lucerne cxl. Two weeks after driving it an hour away from town, my car suddenly stopped driving in drive. It will reverse and drive in gears 1,2, and 3. But once the gear is shifted to drive it will not move but rev the engine. Like its in neutral. There were no warning signs or noises before this happened. Some people tell me it may be something with the transmission, but I'm not sure. I was low on fluid after my trip, but once filled nothing changed. I'm confused to what could be the issue. Any information would be helpful.

How long has your 2007 Buick Lucerne had this problem?

Few weeks