It sounds like your driver side motor mount is deteroauted. I'm willing to bet on that more than the tranny mount. Not saying that isn't worn as well, but more than likely the engine mount. My car did the exact same thing till I did both the mounts. They had 170k on them since the last replacement since 280k. They were just next to about collapsed.

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k