How did he learn from all his teachers?
Rashi: Refer to 119:98:2:1.
Radak: I learned and took Musar (correction) from all of them. From them I contemplated the good path, and they taught me that Your Edos should be my talk.
Malbim: No, the verse means that also Edos (like Mitzvos, in the previous verse) made him wiser than all his teachers. This is because whatever a person investigates in Divine matters with human intellect, he will not attain the Emes. However, via Edos ha'Torah, he knows how Hashem created the world, all the deeds that were in the generations, and all foundations of Emunah, Hashgachah, reward and punishment... All is known via Edos.
What is the meaning of "Sichah Li"?
Rashi: All my talk was in them.
