yeah I had the same probs and am slowly bringing the temps down. My temps now are about 90% not what I want but its going to have to do for now My temps were also at 109 with my closet door closed . Gave me lots of work to bring the temps down 18% with the door closed.
Few things I did to bring the heat down.
my space is 2x4x7.
1 250CFM booster exhaust fan on top (35bucks H.D.)
1 80CFM booster blowing fresh air at the bulb thru a cool tube(cool tube made from our FAQs)then throwing the hot air out of the cab box
1 80CFM booster blowing fresh air at the bottom
1 reg small fan blowing at the plants

and I will be adding a 100CFM cpu fan to blow more fresh to try to bring the temps down to my DREAM temps. Hopefully this helps

DAMN 5 FANS

Hope all is good and u resolve ur problem and yes you will be making more holes in ur cab box