Questions for Exclusive pumpers

Megan • Trying for our third! First baby a miscarriage, chemical then rainbow. Second baby 9 months of trying 4 with clomid. Hoping for a quick easy pregnancy for #3
I am thinking about going to exclusive pumping I have had a terrible time breastfeeding I have used shield got his tongue tie fixed met with several lactation Constanta and none of it is working! He still latches and comes off or doesn't latch at all and just screams and cries...
So about how many times a day do you pump and how many hours in between? 
Do you have your lo on more of a schedule with a certain amount of oz? 
What do you do at night? How many times do you pump at night? Do you feed you Lo more oz before going to bed or when waking up? 
Thanks!!