advice about mix feeds

To start with, I breast fed then offered formula about 30-40 mins after a feed to get more of a supply.
Now I pump 2x a day which makes about 4-5oz for the following day (so 1 bottle), breast feed once in morning and most days once in evening, then do the rest of the feeds as formula x

I literally pump 3 maybe 4 times a day if I have enough for 1 bottle then full breast milk but sometimes I only get 1oz ( 30 mls) in which case I top up with formula mixing the two and the rest are just formula x

My 2 week old gets around 2 bottles of formula a day, 1 before we go to bed and another as and when we need it (often around 4.30pm to give us a breather at navigating early evening with our toddler). The rest of the time he lives on my boob, he might get a formula top up if he’s been on me longer than an hour, doesn’t seem satisfied, and I’ve lost the will to live. I pump when he’s having his nighttime bottle and try to pump at least once during the day - I never get much tho, I actually find I get more in my haakaa during a feed. I got very stressed trying to breastfeed my first, so this time around I’m just trying to go with the flow. If I can spend all day breastfeeding him then I’ll do that, if my toddler needs me then my husband will give him a bottle of formula and i’ll pump when I next can. I’m trying to build a stash of expressed milk, but mostly letting him have formula so I don’t feel stressed about only having 30 or 40ml of breast milk to offer him.