Combi feeding: expressed and formula

[MrsPicklesonSmythe]

Just looking for some advice. I’m on baby 3 but with large gaps and only enough breastfeeding experience to know that I actively dislike it. I’ve never managed to get it right, I find it painful and dont enjoy it even on the rare occasion I do get latch right.
I’d like to provide as much breast milk as possible though so have hired a medela double pump. I already have bottles and formula to use alongside and I understand that I’m basically doing worst of both worlds but if I can achieve a month of mixed feeding I’ll be happy. My older children are at school and old enough to give me time to do this temporarily.

I’d like to know when to start. should I breastfeed colostrum for the first 2-3 days then Switch to pumping?
How often should I pump if I’m to maintain enough supply to achieve what I’d like? What sort of times should I be aiming for? I know I’ll have to pump at night, how many times is sensible?

Any help advice much appreciated.