Breastfeeding/pumping

Hi mamas does anyone have any tips on how to increase my milk supply quite a bit more, I'm breastfeeding my son for 4 1/2 months now and I've started to introduce bottles at night with a little cereal so he'd stay fuller longer at night and hopefully get a better sleep in and I pumped tonight how I usually would and it was about 20-25 minutes and I only got out 1/2 oz when I'd normally get about 3-6 oz's out.

Ive recently started drinking body armor the last two days since I've heard it can help increase supply and I don't know what's wrong and why I'm not making as much anymore, my son eats every 2-3 hours and I breastfeed him more then I do bottles someone please help me out I'm also a ftm so everything is new to me, I have a Medela pump in style and I don't really like it but it's all my insurance had at the time does anyone know if I could get a new one trough insurance or if it's kinda like a one and done thing I don't know 😣😣😣