Ice Strike mana Cost to High

i play an ice strike monk and the base mana cost on a LVL 19 gem is 42 mana i have a staff with +4 melee skills and now the costs are at 66 mana. my attack time is at 0,27 so close to 4 hits per sec. i need to skill the 18% reduced mana cost its totaly mandetory .. without its not playable ..
with some supports on gem i hit 0,21 attack time and 59 mana thats 240 mana per sec at 1000 mana pool so i can hit for 4 sec before i am dry. i cant do bossfights because my mana flask is not big enough ... i need a FuelTankTruck full of mana to sustain any bossfight.

are you seriously complaining about one of the top 3 most overpowered builds currently in the game?

To solve your problem: mana regen

Or run a lower level lol

I had this problem until I got mana leech on gloves and now I always have full mana, that's how good that stat is and you only need it on one item.