Diana Mana Issues

Ive noticed that Diana has more mana issues then most the other mid laners i play. i mained her during the 2014 season and was glad to see the tweak to her ult in patch 4.21 but i am disapointed that this mana issue hasnt been looked at. at low levels you are basically forced to buy a mana item running her combo pretty much puts u from full mana to zero also yet again leaving her dead jin the water. (lvl 6-10) at later levels the mana isnt an issue but at low levels im just saying she needs a base mana increase for sure. ALSO WHY NO BLOOD MOON DIANA like SERIOUSLY