How to stop breastfeeding

My baby is 5 months and I’m overwhelmed with breastfeeding. I pump at work and usually nurse at night. With working full time pumping is beginning to get overwhelming. I’m finding the little time I’m home from work I still need to pump bc my schedule from pumping while at work doesn’t always line up with when baby needs to eat. Anyways I’m just over being tied to a pump and always washing and getting pump parts together. I feel like I want to quit and transition to formula. I have about a months worth or more of a freezer stash. Any tips on how to transition to formula and what formulas would be best? Also how to stop breastfeeding without getting mastitis?