Suggestions to improve this lightning strike build pls

With the level of gear that went into making it, i expected to slaughter bosses with vaal pact+ leech recovering all damage almost instantly. But instead i ended up with a very medicore build.

What am i doing wrong?

Life leech gem is bullshit.
It kills a support gem slot, that could be used for another ~40% more overall damage.

Your gem setup is weird.
Are you using all of this/expecting it to work?
Or are you just levelling those gems?
What do you think Cwdt +spell totem +wrath is doing? (answer: nothing)

Your tree is fine (probably not min-maxed to the end, but fine), but Vaal Pact is not too great of an idea if you're not seriously stacking Life Leech. In your case, it would be better not to use it.

You should put Immortal Call in one of your many CwDt setups, it will provide a lot of protection.

And put "Increased crit damage" in BoR instead of Life Leech.

Where's your accuracy at?
You don't get any from gear, so I doubt it's doing its job.

Also: use Auras.
Herald of Ash, Hatred, Determination, Grace, those exist for a reason.