Despite Qui-Gon's reassurance, Obi-Wan still had this sinking feeling in his stomach. A growing feeling that he was alone in his endeavor to help Anakin. It was... a very sad and lonely feeling.

"When was the last time you tried?"

Because Anakin had made great strides in the last few months. There had been some trying times, certainly, but not like that time when he thought he was losing him.

"Anakin needs support, as much as can be had. Especially now, after what has been said."

He was of course referring to Leia's recent warning.