>12:18:19 [INFO] [Free memory: [m 3,140 MB. [m
Java likes to go up to Xmx even when it doesn't need it, and never frees it. Set Xmx to 3G and it'll probably still work, as you were only using 2G at that point.
edit: Oh, should also mention I won't be working on TT properly either for a while...