I can't produce enough breast milk. Should I consider infant formula?

You can try to do power pumping method to see if your milk supply will increase. Otherwise, just let your baby to latch more often as baby's suckle is the most powerful pump. If you are stressed over milk production, it is perfectly fine to feed infant formula to your baby, as happy mother=happy baby. You do not need to feel guilty and you have to take care of your mental health. I have a friend who was insisted on giving breastmilk and spent time doing pumping and neglected her baby. During the pumping, she always stressed over the milk supply. Now her reflected back and told me how she wished to let go a bit on giving breastmilk and spend more time with baby during his newborn period.